Search

Laonice (Laonice) persica sp. nov. Figs 1A–H, 6. LSID: urn:lsid:zoobank.org:act: B598C9EF-4924-44C0-B42C-403558109C1C Holotype. MNCN16.01 /19125, Persian Gulf, Iran, st. 19, 27°29.156′N, 52°34.003′E, 19 m depth, 34.9% of gravels (0.5‒10 mm), 5.8% of silt and clay (Paratypes. MNCN16.01 /19126, 2 specimens, Persian Gulf, Iran, st. 8, 27°30.229′N, 52°33.574′E, 19 m depth, 45.1% of gravels (0.5‒10 mm), 7.8% of silt and clay (Description. Body 0.4–0.5 mm wide (0.4 mm in holotype, one anterior fragment with 51 chaetigers and one short middle fragment with 18). Posterior region not collected. Prostomium fused with peristomium at fronto-lateral margins (Fig. 1A, G), anteriorly rounded, posteriorly extending to chaetiger 23–26 (26 in holotype) as a low narrow caruncle. Nuchal organs as U-shaped ciliary bands on both sides of caruncle. Occipital antenna large (absent in paratypes, without traces of attachment). Two pairs of eyes in trapezoidal arrangement; median pair large, bean-shaped; lateral pair small, located ahead, set wider apart and often deeply embedded into tissue (Fig. 1A). Branchiae from chaetiger 2 to 31–34 (32 in holotype), shorter than notopodial postchaetal lamellae at chaetiger 2; 1.5–2 times longer than notopodial postchaetal lamellae on following 15 chaetigers, more than twice longer at midbody (due to decreasing length of notopodial postchaetal lamellae) and shorter than notopodial postchaetal lamellae on last two branchiate chaetigers. Notopodial postchaetal lamellae ear-like on anterior 25–30 chaetigers (Fig. 1C–E), narrowing upwardly, usually with acute tips on first four chaetigers, then tips becoming slightly rounded. Largest notopodial lamellae from chaetiger 4–10, with tips touching dorsally at chaetiger 4, significantly shortening along postbranchiate region, becoming rounded above and reduced below notochaetal fascicle/notopodium insertion level (Fig. 1F). Neuropodial postchaetal lamellae ear-like, almost triangular (Fig. 1C–E), largest on chaetigers 8–22, shortening afterwards, becoming very short and hardly detectable on postbranchiate chaetigers (Fig. 1F). Dorsal transverse crests connecting notopodial postchaetal lamellae absent (Fig. 1B). Lateral inter-neuropodial pouches starting from chaetiger 4–6 (5 in holotype), not visible after chaetiger 32–34. Capillaries of anterior chaetigers arranged in two vertical rows. Neuropodial hooks from chaetiger 29–32, up to seven per neuropodium, with one pair of lateral small apical teeth and a single superior median tooth above main fang, appearing tridentate in lateral view (Fig. 1H). Notopodial hooks not seen. Sabre chaetae from chaetiger 17–22 (20 in holotype), one per fascicle. Pygidium not seen, missing. Pigmentation absent. Methyl Green staining. Strong in upper parts of notopodial postchaetal lamellae from chaetiger 4 to 8–10 (Fig. 1G); very weak and diffuse on ventral surface of chaetigers 24–35, where it fades remarkably sooner than on notopodial postchaetal lamellae. Type locality. Persian Gulf, Iran, northwest of Naband Gulf (27°29.156′N, 52°34.003′E), 19 m depth. Etymology. The specific epithet persica derives from the toponymic name of the inlet where the types were collected, the Persian Gulf. Distribution. Persian Gulf (Indian Ocean) (Fig. 6). Remarks. The existence of specimens having and lacking occipital antenna is not unique to L. persica sp. nov., having been also reported in the type-material of L. bahusiensis (Sikorski et al. 2021b). Laonice persica sp. nov. has the prostomium completely fused with the peristomium, which places the species in L. (Laonice) as defined by Sikorski et al. (2017). It also lacks entire dorsal transverse crests connecting the notopodial postchaetal lamellae, and so belongs to the L. cirrata complex, together with L. brevicornis (Kinberg, 1866) [including the junior synonyms L. aperata Radashevsky & Lana, 2009 and L. petersenae Radashevsky & Lana, 2009], L. quadridentata Blake & Kudenov, 1978, L. bassensis Blake & Kudenov, 1978 (likely), L. shamrockensis Sikorski, 2003, L. asaccata Sigvaldadóttir & Desbruyères, 2003, L. pinnulata Radashevsky & Lana, 2009, L. cricketae Sikorski & Pavlova, 2016, and L. plumisetosa Bogantes et al., 2018. However, L. cirrata is much larger (adults up to 5 mm wide), with hooks usually appearing bidentate in lateral view (tridentate in L. persica sp. nov.) and with lateral inter-neuropodial pouches appearing from chaetiger 52 (absent after chaetiger 32–34 in L. persica sp. nov.). Laonice brevicornis has tridentate hooks in lateral view and worms are not large (1.5–2 mm wide), but inter-neuropodial pouches are either absent or present only from chaetigers 3–17. Laonice cricketae has nuchal organs reaching chaetiger 20 and lateral inter-neuropodial pouches appearing only from chaetiger 40 (5–6 in L. persica sp. nov.), while the fusion of prostomium and peristomium is not so evident. Finally, L. shamrockensis, L. asaccata, L. pinnulata and L. plumisetosa have nuchal organs reaching chaetiger 5, 4, 7 and 1, respectively (23–26 in L. persica sp. nov.), while lateral inter-neuropodial pouches appear from chaetiger 3 in L. shamrockensis, L. pinnulata and L. plumisetosa and are absent in L. asaccata (5–6 in L. persica sp. nov.). Nuchal organ are also remarkably shorter in L. quadridentata (reaching chaetiger 18) and L. bassensis (reaching chaetiger 7)., Published as part of Sikorski, Andrey, Pavlova, Lyudmila, Martin, Daniel & Gil, João, 2023, New sublittoral species of Laonice (Annelida: Spionidae) from southern Asian coasts, pp. 490-508 in Zootaxa 5277 (3) on pages 492-494, DOI: 10.11646/zootaxa.5277.3.3, http://zenodo.org/record/7890125, {"references":["Sikorski, A. V., Radashevsky, V. I., Castelli, A., Pavlova, L. V., Nygren, A., Malyar, V. V., Borisova, P. B., Mikac, B., Rousou, M., Martin, D., Gil, J., Pacciardi, L. & Langeneck, J. (2021 b) Revision of the Laonice bahusiensis complex (Annelida: Spionidae) with a description of three new species. Zootaxa, 4996 (2), 253 - 283. https: // doi. org / 10.11646 / zootaxa. 4996.2.2","Sikorski, A. V., Gunton, L. M. & Pavlova, L. V. (2017) Laonice species (Polychaeta, Spionidae) from the Whittard Canyon (NE Atlantic) with descriptions of two new species. Journal of the Marine Biological Association of the United Kingdom, 97 (5), 961 - 973. https: // doi. org / 10.1017 / S 0025315417000480","Kinberg, J. G. H. (1866) Annulata Nova. Ofversigt af Kongliga Vetenskaps-Akademiens Forhandlingar, 22 (4), 239 - 258. [1865]","Radashevsky, V. I. & Lana, P. C. (2009) Laonice (Annelida: Spionidae) from South America. Zoosymposia, 2, 265 - 295. https: // doi. org / 10.11646 / zoosymposia. 2.1.19","Blake, J. A. & Kudenov, J. D. (1978) The Spionidae (Polychaeta) from southeastern Australia and adjacent areas with a revision of the genera. Memoirs of the National Museum of Victoria, 39, 171 - 280. https: // doi. org / 10.24199 / j. mmv. 1978.39.11.","Sigvaldadottir, E. & Desbruyeres, D. (2003) Two new species of Spionidae (Annelida: Polychaeta) from Mid-Atlantic ridge hydrothermal vents. Cahiers de Biologie Marine, 44 (3), 219 - 225. https: // doi. org / 10.21411 / CBM. A. 88043 A 64","Sikorski, A. V. & Pavlova, L. V. (2016) Three new species of Laonice (Polychaete: Spionidae) from West and Southwest Africa. Zootaxa, 4097 (3), 353 - 368. https: // doi. org / 10.11646 / zootaxa. 4097.3.4","Bogantes, V. E., Halanych, K. M. & Meissner, K. (2018) Diversity and phylogenetic relationships of North Atlantic Laonice Malmgren, 1867 (Spionidae, Annelida) including the description of a novel species. Marine Biodiversity, 48 (2), 737 - 749. https: // doi. org / 10.1007 / s 12526 - 018 - 0859 - 8"]}

Laonice (Laonice) Malmgren, 1867 Laonice (Laonice): Sikorski, Gunton & Pavlova 2017: 962. Diagnosis. Prostomium obviously fused with fronto-lateral peristomial margins. Caruncle long, highly variable in length but extending beyond half of branchiate chaetigers. Capillary chaetae in two vertical rows on anterior chaetigers. Hooded hooks with main fang surmounted by one or two paired apical teeth. Notopodial hooks absent. Continuous dorsal transverse crests in postbranchiate region present or absent., Published as part of Sikorski, Andrey, Pavlova, Lyudmila, Martin, Daniel & Gil, João, 2023, New sublittoral species of Laonice (Annelida: Spionidae) from southern Asian coasts, pp. 490-508 in Zootaxa 5277 (3) on page 492, DOI: 10.11646/zootaxa.5277.3.3, http://zenodo.org/record/7890125, {"references":["Malmgren, A. J. (1867) Annulata Polychaeta Spetsbergiae, Gronlandiae, Islandiae et Scandinaviae hactenus cognita. Ofversigt af Kongl. Vetenskaps-Akademiens Forhandlingar, 24, 127 - 233.","Sikorski, A. V., Gunton, L. M. & Pavlova, L. V. (2017) Laonice species (Polychaeta, Spionidae) from the Whittard Canyon (NE Atlantic) with descriptions of two new species. Journal of the Marine Biological Association of the United Kingdom, 97 (5), 961 - 973. https: // doi. org / 10.1017 / S 0025315417000480"]}

Laonice (Sarsiana) andamanica sp. nov. Figs 4A–L, 6. LSID: urn:lsid:zoobank.org:act: FBB97F5C-9A68-44F9-8D6A-02FC0407ED83 Holotype. MNCN16.01 /19135, Andaman Sea, off Myanmar /Burma, st. E14, 15°07.334′N, 94°46.852′E, 47.4 m depth, 77% of silt and clay (Paratype. MNCN16.01 /19136, Andaman Sea, off Myanmar /Burma, st. E13B, 15°07.537′N, 94°46.854′E, 47 m depth, 85% of silt and clay (Description. Holotype incomplete, 0.7 mm wide, in three fragments with 37 (anterior) and 6 plus 2 (middle) chaetigers. Paratype incomplete, 0.7 mm wide, with 22 anterior chaetigers. Prostomium T-shaped, with rounded anterior margin, joined to peristomium, with junction clearly outlined, but completely lacking a space between prostomium and peristomium (Fig. 4A). Caruncle visible, extending to posterior border of chaetiger 7–9. Nuchal organs extending to end of chaetiger 9–11, as U-shaped ciliary bands on sides of caruncle. Palps not seen. Long, acute occipital antenna on posterior prostomial region, as long as notopodial postchaetal lamellae of chaetiger 1. One pair of eyespots in front of occipital antenna (Fig. 4A). Branchiae from chaetiger 2 (Fig. 4A, C), narrowing into thread-like tips (Fig. 4F–G), shorter than notopodial postchaetal lamellae until chaetiger 4 (those on chaetigers 2–3 being half long), as long as on chaetigers 5–8, and slightly longer (approx. 1.2 times— Fig. 4A, G) until chaetiger 27–28; last pair visible on chaetiger 35 (Fig. 4B, H). Notopodial postchaetal lamellae much longer than branchiae on posteriormost branchiate region (Fig. 4B, H), up to four times longer than last pair of branchiae. Notopodial postchaetal lamellae narrowing to acute tips until chaetiger 42 (Fig. 4I), gradually lengthening to end of branchiate region (Fig. 4B), then considerably longer from chaetiger 29–35, being twice as long on chaetiger 35 than on chaetigers 5–8 (Fig. 4F, H) and three times longer than on chaetiger 2, and sharply decreasing on the postbranchiate chaetigers (Fig. 4J). Tips of lamellae acute, gradually extending to increasingly narrow, long, sharply pointed processes from chaetigers 18–29 (Fig. 4H), lacking acute tips backwards (Fig. 4J). Tips of lamellae reaching opposite chaetal tuft (Fig. 4B). Notopodial postchaetal lamellae ear-like, with rounded upper edges from chaetiger 42 (Fig. 4J). Inferior regions of notopodial postchaetal lamellae (below neuropodial chaetal tuft) becoming visible from chaetiger 31 (Fig. 4H–J). Neuropodial postchaetal lamellae axe-shaped, with upper lateral angle forming an acute tip anteriorly, progressively becoming more rounded on posterior chaetigers (Fig. 4F–J). Noto- and neuropodial prechaetal lamellae short, not easily distinguishable. Continuous dorsal transverse crests connecting notopodial postchaetal lamellae first appearing three chaetigers before last branchiate one; maximum height at chaetigers 35–37 (Fig. 4B); present up to the last chaetiger of holotype. Transverse nototrochs quite pronounced anteriorly on several branchiate chaetigers. Lateral inter-neuropodial pouches from chaetiger 26, up to at least chaetiger 37 in holotype anterior fragment. Capillaries of anterior chaetigers arranged in two vertical rows. Neuropodial hooks from chaetiger 34, up to eight per fascicle, tridentate in lateral view (Fig. 4K), quadridentate in frontal view, with one pair of small apical teeth side by side and a single superior median tooth above main fang (Fig. 4L). Notopodial hooks absent in holotype. Sabre chaetae from chaetiger 27. Pygidium not seen, missing. Pigmentation absent. Methyl Green staining. Strong on inner upper parts of notopodial postchaetal lamellae from chaetiger 5–10, on dorsal and ventral side of peristomium, on prostomium below eyespots and behind occipital antenna, and ventrally in front of mouth (Fig. 4C–D). Very weak, diffuse staining ventrally and on neuropodial postchaetal lamellae of chaetigers 25–32 (Fig. 4E), fading remarkably sooner than on notopodial postchaetal lamellae, prostomium and peristomium. Type locality. Andaman Sea, off Myanmar /Burma (15°07.334′N, 94°46.852′E), 47.4 m depth. Etymology. The specific epithet andamanica derives from the toponymic name of the sea where the types were collected, the Andaman Sea. Distribution. Andaman Sea (Indian Ocean) (Fig. 6). Remarks. The holotype was the single specimen having enough chaetigers to determine the main numerical characters. Laonice andamanica sp. nov. belongs to L. (Sarsiana) as defined by Sikorski et al. (2017), as it has comparatively short nuchal organs (similar in length in all studied specimens) and capillaries of the anterior chaetigers arranged in two vertical rows only. Moreover, it has dorsal transverse crests, but apparently lacks the membrane connecting the anterior angles of prostomium and peristomium, as well as hooks in most posterior notopodia. Thus, it most closely resembles L. japonica (Moore, 1907), L. sinica Sikorski & Wu, 1998, L. praecirrata, L. branchiata Nonato, Bolívar & Lana, 1986 and L. magnacristata. Laonice andamanica sp. nov. can be easily distinguished from these species in having several notopodial postchaetal lamellae of posterior branchiate chaetigers with pointed tips elongated into narrow long lanceolate processes with length equal to the body width on the last branchiate chaetigers (Fig. 4B, H). Besides, L. japonica has nuchal organs reaching chaetiger 18 (9–11 in L. andamanica sp. nov.) and lateral inter-neuropodial pouches appearing from chaetiger 4 (26 in L. andamanica sp. nov.); L. sinica has lateral inter-neuropodial pouches from chaetiger 5–9 and a different shape of dorsal transverse crests; L. magnacristata is 0.4 mm wide, has nuchal organs reaching chaetiger 2, 4–7 pairs of branchiae (34 pairs in L. andamanica sp. nov.), sabre chaetae from chaetiger 6 (27 in L. andamanica sp. nov.), and lateral inter-neuropodial pouches from chaetiger 7–8; and L. praecirrata has nuchal organs extending until chaetiger 15–21 and the membrane connecting prostomium with peristomium at the anterior angles is sunken in the groove between them. Finally, the lateral inter-neuropodial pouches in L. branchiata [species mistakenly placed in L. (Laonice) by Sikorski et al. (2017)] start from chaetiger 4–10 (instead of 26 in L. andamanica sp. nov.). Laonice andamanica sp. nov. has the prostomium joined to the peristomium, but the junction still clearly outlined. This unique feature is shared with L. branchiata (see Sikorski 2011) and, probably, is also present in L. japonica (see Sikorski 2003b), which allows us to suggest that these species form a distinctive morphological group within the genus. However, the relevance of this group requires further confirmation., Published as part of Sikorski, Andrey, Pavlova, Lyudmila, Martin, Daniel & Gil, João, 2023, New sublittoral species of Laonice (Annelida: Spionidae) from southern Asian coasts, pp. 490-508 in Zootaxa 5277 (3) on pages 499-501, DOI: 10.11646/zootaxa.5277.3.3, http://zenodo.org/record/7890125, {"references":["Sikorski, A. V., Gunton, L. M. & Pavlova, L. V. (2017) Laonice species (Polychaeta, Spionidae) from the Whittard Canyon (NE Atlantic) with descriptions of two new species. Journal of the Marine Biological Association of the United Kingdom, 97 (5), 961 - 973. https: // doi. org / 10.1017 / S 0025315417000480","Moore, J. P. (1907) Descriptions of new species of Spioniform Annelids. Proceedings of the Academy of Natural Sciences of Philadelphia, 59, 195 - 207.","Sikorski, A. V. & Wu, B. L. (1998) Laonice sinica sp. nov. from the Yellow Sea. Zoologichesky Zhurnal, 77 (11), 1242 - 1248. [in Russian]","Nonato, E. F., Bolivar, G. A. & Lana, P. C. (1986) Laonice branchiata, a new species of Spionidae (Annelida: Polychaeta) from the southeastern Brazilian coast. Neritica, 1 (3), 21 - 27. https: // doi. org / 10.5380 / rn. v 1 i 3.41193","Sikorski, A. V. (2011) Review of Laonice (Spionidae, Annelida) with remarks on several species and a description of a new species from South Africa. Italian Journal of Zoology, 78 (S 1), 201 - 214. https: // doi. org / 10.1080 / 11250003.2011.617218","Sikorski, A. V. (2003 b) On the fauna of the genus Laonice (Polychaeta, Spionidae) in the northern Pacific. Zoologichesky Zhurnal, 82 (10), 1179 - 1190. [in Russian with English Summary]"]}

Laonice (Laonice) siamica sp. nov. Figs 2A–I, 6. LSID: urn:lsid:zoobank.org:act: 545BCAEE-01D8-454F-960D-86B54F9025DA Holotype. MNCN16.01 /19128, Gulf of Siam, off Thailand, st. 5, 07°36.018′N, 102°50.543′E, 64 m depth, 92.2% of silt and clay ( Description. Holotype 0.7 mm wide, 20 mm long for 104 chaetigers (one anterior fragment of 60 chaetigers and one posterior with 44). Prostomium fused with peristomium at fronto-lateral margin (Fig. 2A, C), anteriorly rounded, extending posteriorly to beginning of chaetiger 41 as a low narrow caruncle, accompanied by nuchal organs as lateral ciliary bands. Occipital antenna thin, erect, half length of notopodial postchaetal lamellae of chaetiger 1. One pair of small, distinct, faded brownish eyespots in front of attachment of occipital antenna. Branchiae from chaetiger 2; first pair half as long as notopodial postchaetal lamellae, then increasing their length but still shorter until chaetiger 4 (Fig. 2A, E), of equal length on chaetiger 5, and twice longer after chaetiger 10 (Fig. 2F); then branchiae gradually shortening from chaetiger 38 (Fig. 2B, G), being absent after chaetiger 50 (last branchiate chaetiger). Notopodial postchaetal lamellae leaflike, almost triangular, with narrow acute tips through all body (Fig. 2A–C, E–G), but particularly pronounced on the four anteriormost chaetigers (Fig. 2A, E), gradually shortening to half the length of anterior ones on last branchiate chaetigers, becoming narrow triangles on posteriormost chaetigers (Fig. 2G). Anterior postbranchiate chaetigers with notopodial postchaetal lamella extending slightly dorsally, not reaching middle dorsum (Fig. 2B). Neuropodial postchaetal lamellae almost trapezoidal anteriorly (Fig. 2E), then triangular, with acute tips through all body (Fig. 2F–G). Dorsal transverse crests absent. Lateral inter-neuropodial pouches from chaetiger 5–6, irregularly present from chaetiger 50 to posteriormost chaetigers. Capillaries of anterior chaetigers arranged in two vertical rows. Neuropodial hooks from chaetiger 39, up to 6–8 per fascicle, bidentate in lateral view, tridentate in frontal view, with one pair of small apical teeth side by side above main fang (Fig. 2H–I). Notopodial hooks absent. Sabre chaetae from chaetiger 14, one per fascicle. Pygidium with ten lobes forming a ring around the anus: four bilaterally symmetrical pairs bearing one thin threadlike anal cirrus, and one ventral pair closely set, pointed and lacking cirri (Fig. 2D). Pigmentation absent. Methyl Green staining. As oval spots on upper parts of notopodial postchaetal lamellae of chaetigers 4–8 (Fig. 2C). Type locality. Gulf of Siam, off Thailand (07°36.018′N, 102°50.543′E), 64 m depth. Etymology. The specific epithet siamica derives from the toponymic name of the inlet where the type was collected, the Gulf of Siam. Distribution. Gulf of Siam (Pacific Ocean) (Fig. 6). Remarks. Laonice siamica sp. nov. can be referred to L. (Laonice) as defined by Sikorski et al. (2017), as it has the prostomium completely fused with the peristomium. It is closely related to the L. cirrata complex [L. brevicornis (with both L. aperata and L. petersenae included), L. quadridentata, L. cricketae and, probably, L. bassensis, L. shamrockensis, L. asaccata, L. pinnulata and L. plumisetosa]. However, the gradual reduction of the posterior branchiae is quite unique of L. siamica sp. nov. While measuring only 0.7 mm wide, the holotype of L. siamica sp. nov. has nuchal organs extending to chaetiger 41 and up to 50 pairs of branchiae, which only occurs in specimens of L. cirrata measuring> 2.2 mm wide. Nuchal organs of L. shamrockensis, L. asaccata, L. pinnulata and L. plumisetosa are much shorter and do not extend over chaetiger 7 (41 in L. siamica sp. nov.). In L. brevicornis and L. cricketae nuchal organs are shorter as well: up to chaetiger 26 in L. brevicornis (with last branchiae on chaetiger 36) and up to chaetiger 20 in L. cricketae (with last branchiae on chaetiger 39 and lateral inter-neuropodial pouches only from chaetiger 40, instead of chaetiger 7 in L. siamica sp. nov.). Nuchal organs, as in the case of the species described above, are also remarkably shorter in L. quadridentata (up to chaetiger 18) and L. bassensis (up to chaetiger 7).

Four new species of Laonice (Annelida: Spionidae) are described from the southern and southeastern coasts of Asia: L. (Laonice) persica sp. nov., L. (Laonice) siamica sp. nov., L. (Sarsiana) apicelamella sp. nov. and L. (Sarsiana) andamanica sp. nov. Materials were collected within the scope of different environmental surveys performed by the consulting company Creocean, ranging from the Persian Gulf (Indian Ocean) on the west, to the Gulf of Siam (Pacific Ocean) on the east. In addition, specimens found in the Gulf of Siam are tentatively attributed to L. (Sarsiana) sinica, and an English translation of the species description is provided for the first time. Different species subgroups within L. (Sarsiana) are also recognized based on key morphologic characters, though their phylogenetic relevance requires further confirmation. The scientific value of biological material collected during environmental surveys is emphasized, and contractors are encouraged to deposit reference collections in public natural history collections. Norwegian Research Council Project 233635/H30; Consolidated Research Group on Marine Benthic Ecology of the Generalitat de Catalunya (2021SGR00405); info:eu-repo/semantics/publishedVersion

Laonice Malmgren, 1867 (emended) Type species: Nerine cirrata M. Sars, 1851. By monotypy. Diagnosis. Prostomium anteriorly rounded or slightly concave, either T- or skittle-shaped, clearly fused with peristomium at anterior angles (subgenus Laonice), fused only by a thin membrane normally sunken in a groove between prostomium and peristomium (part of subgenus Sarsiana), or not fused at all (part of subgenus Sarsiana and subgenus Appelloefia). Occipital antenna present (most usual), absent or with variable presence (e.g., in Laonice bahusiensis Söderström, 1920). Caruncle well developed, long (except in the deep-sea species Laonice (Sarsiana) magnacristata Maciolek, 2000 and Laonice (Laonice) plumisetosa Bogantes, Halanych & Meissner, 2018), extending posteriorly over several chaetigers following a pair of nuchal organ loops starting from palp attachments. Nuchal organs long and widely variable in length (subgenus Laonice) or short (usually around 10 chaetigers, always less than 20) and less variable in length (subgenera Sarsiana and Appelloefia). Palps often long, without sheath at base. Peristomium not fused with chaetiger 1. Parapodia biramous; each ramus of anterior chaetigers with three tufts of long, thin capillary chaetae, including anterior and posterior parallel vertical rows of chaetae arranged in single lines (except in subgenus Appelloefia, with more than two rows of capillaries in several anteriormost chaetigers), with a third tuft inserted above (notopodia) and below (neuropodia) these rows. Inferior neurochaetae or sabre chaetae [“Haarborsten” in Söderström (1920)] appearing in anterior region, being longer and stouter than ordinary capillaries. Neuropodial hooks with primary hood only, with chaetiger of first appearance varying; notopodial hooks generally absent (may be present in posteriormost chaetigers in some species of subgenus Sarsiana). Dorsal branchiae from chaetiger 2, separated from notopodial postchaetal lamellae and on a variable number of anterior chaetigers, rarely up to body end (e.g., in subgenus Appelloefia). Lateral inter-neuropodial pouches on a variable number of anterior chaetigers, often up to body end, rarely absent; first chaetiger with pouches varying. Anus terminal, surrounded by two ventral lobes or small papilliform cirri (usually placed close together) and several pairs of comparatively long, thinner dorsal anal cirri. Pigmentation absent., Published as part of Sikorski, Andrey, Pavlova, Lyudmila, Martin, Daniel & Gil, João, 2023, New sublittoral species of Laonice (Annelida: Spionidae) from southern Asian coasts, pp. 490-508 in Zootaxa 5277 (3) on page 491, DOI: 10.11646/zootaxa.5277.3.3, http://zenodo.org/record/7890125, {"references":["Malmgren, A. J. (1867) Annulata Polychaeta Spetsbergiae, Gronlandiae, Islandiae et Scandinaviae hactenus cognita. Ofversigt af Kongl. Vetenskaps-Akademiens Forhandlingar, 24, 127 - 233.","Sars, M. (1851) Beretning om en i Sommeren 1849 foretagen zoologisk Reise i Lofoten og Finmarken. Nyt Magazin for Naturvidenskaberne, Oslo, 6, 121 - 211.","Soderstrom, A. (1920) Studien ¸ ber die Polychatenfamilie Spionidae. Almqvist & Wiksells, Uppsala, 288 pp., 1 pl.","Maciolek, N. J. (2000) New species and records of Aonidella, Laonice, and Spiophanes (Polychaeta: Spionidae) from shelf and slope depths of the Western North Atlantic. Bulletin of Marine Science, 67 (1), 529 - 547.","Bogantes, V. E., Halanych, K. M. & Meissner, K. (2018) Diversity and phylogenetic relationships of North Atlantic Laonice Malmgren, 1867 (Spionidae, Annelida) including the description of a novel species. Marine Biodiversity, 48 (2), 737 - 749. https: // doi. org / 10.1007 / s 12526 - 018 - 0859 - 8"]}

Laonice (Sarsiana) sinica Sikorski & Wu, 1998 Laonice sinica Sikorski & Wu 1998: 1243–1247, Figs 1–3, Tabs 1–3 [in Russian]. Material examined. Translated and adapted from Sikorski & Wu (1998). Holotype. ZISP 1 /10363, Kiao Chou Bay, Qingdao, China, st. 43, 17–37 m, silt with shells, 20 June 1957. Paratypes. ZISP 9 /10369, 1 specimen, Chefoo Bay, Yantai, China, st. 52, 10 m, silt, 03 July 1957. Kiao Chou Bay, Qingdao, China, 5–37 m, silt with shells: ZISP 1 /10361 and 12/10372, 2 specimens, st. 3, 37 m, 03 June 1957; ZISP 13 /10373, 1 specimen, st. 18, 17 m, silt, 07 June 1957; ZISP 5 /10365, 8 specimens, ZMUM 1789, 2 specimens, st. 20, 08 June 1957; ZISP 7 /10367, 1 specimen, st. 23, 08 June 1957; ZISP 15 /10375, 1 specimen, st. 24, 17 m, silt, 08 June 1957; ZISP 4 /10364, 2 specimens, st. 41, 5 m, 20 June 1957; ZISP 6 /10366, 1 specimen, st. 42, 27 m, 20 June 1957; ZISP 2 /50406, 5 specimens, ZMUM 1788, 1 specimen, st. 43, 25 m, 20 June 1957. Bohai Sea, China, 10–32 m, silt: ZISP 16 /10376, 1 specimen, st. 110, 18 July 1957; ZISP 8 /10368, 5 specimens, st. 206, 14–26 m, silt, 13 July 1957; ZISP 10 /10370, 2 specimens, st. 209, 23 September 1957. ZISP 14 /10374, 1 specimen, Bohai Strait, China, R / V “ Venus ”, st. 5, 05 July 1958. ZISP 11 /10371, 4 specimens, Yellow Sea, off China, R / V “ Venus ”, st. 201, 20–60 m, sandy silt with stones and broken shells, 27 July 1957. Description of Chinese specimens (translation of the original description). Up to 77 mm long and 1.3 mm wide for 144 chaetigers (re-examination of type material showed size-related data being slightly different from original description); largest incomplete specimen 1.4 mm wide. Prostomium T-shaped with rounded anterior margin, not fused with peristomium at antero-lateral angles. Nuchal organs reaching chaetiger 8–11, as U-shaped ciliary bands on sides of caruncle. Palps reaching chaetiger 19. Short erect occipital antenna. Large bright bean-shaped eyespots in front of occipital antenna, sometimes with additional small pale spots in front. Branchiae from chaetiger 2, short, very gradually lengthening from 1.5 times shorter on chaetiger 2 to nearly as long as notopodial postchaetal lamellae at chaetiger 7–8. Last pair of branchiae on chaetiger 26–42. Notopodial postchaetal lamellae leaf-like, narrowing into sharply acute tips in all branchiate chaetigers, losing acute tips to become round on first 3–4 post-branchial chaetigers, becoming small rounded dorso-laterally shifted protrusions on posterior chaetigers, and finally becoming lanceolate on posteriormost chaetigers. Neuropodial postchaetal lamellae triangular, with acute upper tips becoming round on posterior post-branchial chaetigers. Dorsal transverse crests first appearing on last 4–6 branchial chaetigers, then continuing up to chaetiger 25; first 2–3 as large oval (tongue-shaped) mid-dorsal membranes non-connecting with notopodial postchaetal lamellae; of equal height without any mid elevation from mid postbranchiate region to reach maximum size on last 1–2 branchial chaetigers. Lateral inter-neuropodial pouches from chaetiger 5–9, sometimes larger than parapodia in most posterior chaetigers; usually not visible on posteriormost 12–17 chaetigers. Capillaries of anterior chaetigers arranged in two vertical rows. Neuropodial hooks from chaetiger 27–41, up to 7–13 per fascicle, bidentate in lateral view, tridentate in frontal view, with one pair of small apical teeth very close to each other, side by side above main fang. Notopodial hooks absent. Sabre chaetae from chaetiger 20–36, at first two per fascicle (one in juveniles less than 0.5 mm wide), only one after 6–12 chaetigers. Pygidium with one pair of closely set ventral lobes resembling small tubercles, and up to six bilaterally symmetrical pairs of thin threadlike dorsal anal cirri around anus. Yellow-brown in vivo, non-pigmented when preserved. Methyl Green staining. Lacking a distinct pattern. Biology. Sexually mature females having oocytes 0.13–0.15 mm in diameter found on the 3rd and 20th of June of 1957 at Kiao Chou Bay (Yellow Sea). Mature specimens (with oocytes and sperm) found on the 26–27th of July 1957 at the Yellow Sea, and on the 17th of August 1957 at the Bohai Sea. Type locality. Kiao Chou (= Jiaozhou) Bay (Yellow Sea), 17–37 m depth. Distribution. Laonice (S.) sinica is known from the Yellow and Bohai seas (Pacific Ocean), where it can be dominant in sublittoral communities (Fig. 6). Remarks. The original description of Laonice sinica was published only in Russian by Sikorski & Wu (1998). Here we are presenting the first English translation. The comparison with the specimens collected in the Gulf of Siam can be found in the Remarks for Laonice (Sarsiana) cf. sinica., Published as part of Sikorski, Andrey, Pavlova, Lyudmila, Martin, Daniel & Gil, João, 2023, New sublittoral species of Laonice (Annelida: Spionidae) from southern Asian coasts, pp. 490-508 in Zootaxa 5277 (3) on pages 501-502, DOI: 10.11646/zootaxa.5277.3.3, http://zenodo.org/record/7890125, {"references":["Sikorski, A. V. & Wu, B. L. (1998) Laonice sinica sp. nov. from the Yellow Sea. Zoologichesky Zhurnal, 77 (11), 1242 - 1248. [in Russian]"]}

Laonice (Sarsiana) Sikorski, Gunton & Pavlova 2017 Laonice (Sarsiana): Sikorski et al. 2017: 962. Type species: Laonice sarsi Söderström, 1920. Diagnosis. Prostomium not obviously fused or non-fused with fronto-lateral peristomial margin. Anterolateral prostomial corners sometimes fused to peristomium by an inconspicuous (in dorsal view) membrane, often deeply sunken in prostomium/peristomium groove. Nuchal organs generally short (usually extending up to chaetiger 10). Dorsal transverse crests present or absent. Other numerical characters highly variable. Notopodial hooded hooks may be present in posteriormost chaetigers., Published as part of Sikorski, Andrey, Pavlova, Lyudmila, Martin, Daniel & Gil, João, 2023, New sublittoral species of Laonice (Annelida: Spionidae) from southern Asian coasts, pp. 490-508 in Zootaxa 5277 (3) on page 496, DOI: 10.11646/zootaxa.5277.3.3, http://zenodo.org/record/7890125, {"references":["Sikorski, A. V., Gunton, L. M. & Pavlova, L. V. (2017) Laonice species (Polychaeta, Spionidae) from the Whittard Canyon (NE Atlantic) with descriptions of two new species. Journal of the Marine Biological Association of the United Kingdom, 97 (5), 961 - 973. https: // doi. org / 10.1017 / S 0025315417000480","Soderstrom, A. (1920) Studien ¸ ber die Polychatenfamilie Spionidae. Almqvist & Wiksells, Uppsala, 288 pp., 1 pl."]}

Heterospio bathyala new species Figures 5–6 urn:lsid:zoobank.org:act: 8CFC9701-A0C8-4E39-8ED7-85A67D30E7D4 Heterospio cf. longissima: Blake et al. 1987; Blake & Grassle 1994: 861; Hilbig 1994: 941 (in part). Not Ehlers 1874, 1875; Hartman 1965. Material examined. (27 specimens) Southeastern United States, U.S. South Atlantic ACSAR Program, off Cape Fear, North Carolina, coll. J.A. Blake. Sta. 11, Cruise SA-4, Rep. 1, 22 May 1985, BC, 33.081°N, 76.418°W, 800 m, holotype (USNM 1673076), 2 juvs (USNM 1673077); Rep. 3, 22 May 1985, BC, 33.81°N, 76.423°W, 799 m, 1 juv (USNM 1673078); Cruise SA-5, Rep. 1, 23 Sep 1985, BC, 33.081°N, 76.42°W, 796 m, 1 paratype (USNM 1673079); Rep. 2, 23 May 1985, BC, 33.081°N, 76.2517°W 796 m, 2 paratypes (USNM 1673080); Rep. 3, 23 May 1985, BC, 33.081°N, 76.419°W, 797 m, 2 paratypes (USNM 1673081); Cruise SA-6, Rep. 2, 22 Nov 1985, BC, 33.083°N, 76.419°W, 804 m, 3 paratypes (USNM 1673082); Sta. 14, Cruise SA-4, Rep. 1, 20 May 1985, BC, 33.394°N, 77.019°W, 805 m (4, USNM 1673083); Rep. 2, 20 May 1985, BC, 33.394°N, 77.02°W, 802 m (3, USNM 1673084); Rep. 3, 20 May 1985, BC, 33.395°N, 77.019°W, 803 m (3, USNM 1673085); Cruise SA-5, Rep. 1, 19 Sep 1985, BC, 33.395°N, 77.02° W, 796 m, 1 paratype (USNM 1673086); Rep. 2, 19 Sep 1985, BC, 33.395°N, 77.021°W, 799 m, 1 juv (USNM 1673087); Cruise SA-6, Rep 1, 18 Nov 1985, BC, 33.396°N, 77.018°W, 799 m, 3 paratypes (USNM 1673088); Rep. 3, 18 Nov 1985, BC, 33.395°N, 77.018°W, 799 m (3, USNM 1673089).— Off Cape Lookout, North Carolina. Sta. 3, Cruise SA-3, 14 Jul 1984, BC, 34.242°N, 75.672°W, 1509 m (1, USNM 1673090). Description. All specimens incomplete. Body long, narrow, threadlike; available anterior fragments with 11–14 setigerous segments, divided into thoracic region with 1–7 crowded setigers and setiger 8 as the first elongated segment; these followed 3–6 elongate cylindrical abdominal segments (Figs. 5A, 6A). Most specimens with a total of 11–12 setigerous segments. One posterior fragment terminating in bulbous pre-pygidial region bearing hooked spines (Fig. 6F). Holotype (USNM 1673076) anterior fragment with 12 setigers, 16.5 mm long and 0.23 mm across thoracic segments (Fig. 5A, C); paratype (USNM 1673081) with 12 setigers, 16.7 mm long, 0.28 mm wide; paratype (USNM 1673082) with 13 setigers, 14.25 mm long, 2.7 mm wide. A few mid-body fragments suggest at least 14- setiger specimens collected, but not intact. Juvenile (USNM 1673086) anterior fragment with 11 setigers, 3.1 mm long and 0.1 mm wide. Color in alcohol opaque white to light tan; pigment entirely absent. Pre-setiger region short, only as long as first 1.5 thoracic setigers (Figs. 5A–D, Fig. 6B). Prostomium flattened, disk-like, broadly rounded anteriorly (Fig. 5A–C), with middle of dorsal surface becoming elevated as broad crest extending over peristomium and merging with setiger 1 (Figs. 5A–B, D, 6B), eyespots absent; nuchal organs narrow posterior lateral grooves anterior to first peristomial ring (Fig. 6B). Peristomium with narrow anterior ring separated from large posterior ring by dorsolateral grooves from which dorsal tentacles arise (Figs. 5B, D, 6E); these located laterally; when present, tentacles elongate thickened filaments (Fig. 6A, E); peristomium interrupted by middorsal crest; ventral surface relatively smooth; mouth located mid-ventrally between prostomium and peristomium, consisting of 4–6 short lobes surrounding oral opening (Fig. 5C). Branchiae or their stubs present on setigers 2–4 on all specimens examined except juveniles (Figs. 5A–B, 6A– C, E); most branchiae long, thin, rounded in cross section, tapering to rounded tip; branchiae with narrow ciliated groove; internal blood vessel extends along entire length (Fig. 6B, E). Juveniles with branchiae observed only on setiger 2. All parapodia biramous with setal fascicles arising from near anterior edge of segment. Thoracic region of all specimens including juveniles with seven short setigers, each slightly wider than long; with setiger 8 being first elongate setiger (Fig. 5A), about as long as setigers 1–6, shorter in juveniles; setiger 9 very elongate, about 20x longer than setigers 1–7; setigers 10–12 or 13 each 25–30x longer than thoracic setigers. All thoracic setigers slightly flattened dorsally with parapodia weakly inflated and elevated over dorsum. Abdominal setigers similarly inflated ventrally; abdominal setigers round in cross section. Abdominal parapodia from setiger 10 with parapodia as narrow elongate lobes, becoming thicker and more prominent from setigers 11–12; noto- and neuropodia with distinct dorsal and ventral gaps; lateral gaps between noto- and neuropodia narrower. All thoracic notopodia of setigers1–8 with 12–16 long capillaries in spreading fascicles; capillaries of neuropodia more numerous with 25–30 setae arranged in tight, dense fascicle. Noto- and neuropodia of setigers 9–11 with capillaries in two short transverse rows with wide dorsal and ventral gaps and narrow lateral gaps between noto- and neuropodia; setiger 12 with capillaries (Fig. 5E) and usually a few acicular spines (Fig. 5F) and rarely an aristate spine or thickened capillary in anterior row; setigers 13–14 with numerous acicular spines in anterior row and narrow capillaries in posterior row; aristate spines present or absent. Spines and capillaries of noto- and neuropodia from setiger 13 in longer cinctures, each with 10–12 acicular spines in anterior row and about 25 or more capillaries in posterior row or about 20–24 acicular spines from noto- and neuropodia on a side. Spines flattened, tapering to narrow pointed tip (Fig. 5F), some with a very short aristate tip. Far posterior bulbous section with two parapodia, each bearing 1–2 hooked spines in each ramus. Each spine short, pointed, with curved tip (Fig. 5G). Segments of elongate abdominal region with transverse muscle bands; these believed to support stretching of elongate segments (Blake & Maciolek 2019); continuing until posterior bulbous section. Posterior bulbous section oval-shaped, with terminal anal opening (Fig. 6F). Methyl Green staining. Stain concentrates on peristomium and a few anterior thoracic setigers (Fig. 6C); prostomium not stained; abdominal setigers with stain retained laterally in bands anterior to parapodia and variably along individual segments as irregular speckles (Fig. 6C–D). Remarks. Heterospio bathyala n. sp. is most similar to H. reducta Laubier, Picard & Ramos, 1974 originally reported from deep water (2335 m) in the Mediterranean Sea north of Algeria and H. angolana Bochert & Zettler, 2009 from shelf depths (105–146 m) off Angola, West Africa. All three species have a reduced number of branchiae (three pairs) and the first elongated segment is setiger 8. Heterospio reducta is reported to have only capillary setae in posterior cinctures; however, no specimens with more than 12 setigers have been reported (Laubier et al. 1974; Borowski 1994; Parapar et al. 2014; this study). Heterospio angolana is therefore the species most similar morphologically to H. bathyala n. sp. The two species differ in that H. bathyala n. sp. has a broadly rounded, flattened, disk-like prostomium followed by a raised dorsal crest that extends posteriorly over the peristomium and onto setiger 1; in contrast, the prostomium of H. angolana is conical, narrowing to a rounded tip, and has no dorsal crest. In addition, H. angolana is described as having numerous aristate spines or subuluncini in the anterior setal row from setiger 12 and a posterior row of numerous simple acicular spines. In contrast, H. bathyala n. sp. has an anterior row of simple pointed acicular spines and a posterior row of simple capillaries. A few aristate spines may be present with acicular spines on setiger 12, but are not present on setigers 13–14. Biology. Heterospio bathyala n. sp., although rare, was concentrated at Stations 11 (off Cape Fear, NC) and 14 (off Charleston, NC) along the 800-m isobath, with only a single specimen collected elsewhere in survey areas off the Carolinas. Station 14, with 436 species of benthic invertebrates collected from nine box core samples (0.81 m 2) over three surveys, had the highest species richness and diversity for any site during the entire U.S. ACSAR program sampled from the Canadian boundary to off the Carolinas (Blake et al. 1987; Blake & Grassle 1994). The dominant polychaete at both stations was Microrbinia linea Hartman, 1965, a small threadlike orbiniid that is widespread along the entire U.S. Atlantic continental slope (Blake 2021a). Stations 11 and 14 were adjacent sites in areas influenced by the Gulf Stream and complex local bottom currents (Blake & Grassle 1994); both sites were thought to be depositional and had similar sediments that were well mixed with a water content of about 57%. The nine sediment samples each at Stations 11 and 14 averaged over all three surveys included the following results for percent sand, silt and clay fractions (Blake et al. 1987): Station 11: sand (39 ± 3), silt (33.9 ± 2.5), clay (26.9 ± 1.8); Sta. 14: sand (41 ± 0.7); silt (33.1 ± 1.5); clay (25.87 ± 2.3). Station 14 is in an area of high productivity and sedimentation with an average mean percent total carbon in the sediments of 3.67 ± 0.67. Etymology. The epithet is derived from the Greek, bathys, for deep, denoting the bathyal depths from which this species was collected. Distribution. U.S. continental slope off North Carolina; off Charleston, SC, and Cape Fear, NC, 796–804 m; off Cape Lookout, NC, 1509 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 16-20, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Blake, J. A., Hecker, B., Grassle, J. F., Brown, B., Wade, M., Boehm, P., Baptiste, E., Hilbig, B., Maciolek, N., Petrecca, R., Ruff, R. E., Starczak, V. & Watling, L. E. (1987) Study of Biological Processes on the U. S. South Atlantic Slope and Rise. Phase 2. OCS Study MMS 86 - 0096: Vol. 2. Final Report. National Technical Information Service (NTIS) No. PB 87 - 214342 and PB 87 - 214359. Prepared for the U. S. Department of the Interior, Minerals Management Service, Washington, D. C., ii + 414 pp., 13 Appendices. Available from: https: // espis. boem. gov / final % 20 reports / 4698. pdf (accessed 20 January 2021)","Blake, J. A. & Grassle, J. F. (1994) Benthic community structure on the U. S. South Atlantic slope off the Carolinas: Spatial heterogeneity in a current-dominated system. Deep-Sea Research II, 41 (4 - 6), 835 - 874. https: // doi. org / 10.1016 / 0967 - 0645 (94) 90051 - 5","Hilbig, B. (1994) Faunistic and zoogeographical characterization of the benthic infauna on the Carolina Continental slope. Deep-sea Research II, 41 (4 - 6), 929 - 950. https: // doi. org / 10.1016 / 0967 - 0645 (94) 90055 - 8","Ehlers, E. (1874) Annulata nova vel minus cognita in Expeditione \" Porcupine \" capta. The Annals and Magazine of Natural history, Series 4, 13, 292 - 298. [https: // www. biodiversitylibrary. org / page / 24342680]","Ehlers, E. (1875) Beitrage zur Kenntniss der Verticalverbreitung der Borstenwurmer im Meere. Zeitschrift fur wissenschaftliche Zoologie, 25, 1 - 102, 4 pls. [https: // www. biodiversitylibrary. org / page / 45143254]","Hartman, O. (1965) Deep-water benthic polychaetous annelids off New England to Bermuda and other North Atlantic areas. Allan Hancock Foundation Occasional Paper, 28, 1 - 378, 52 pls. [http: // digitallibrary. usc. edu / digital / collection / p 15799 coll 82 / id / 20299]","Blake, J. A. & Maciolek, N. J. (2019) 7.3. 1.9. Longosomatidae Hartman, 1944. In: Purschke, G., B ˆ ggemann, M. & Westheide, W. (Eds.), Handbook of Zoology. Annelida. Vol. 1. Annelida Basal groups and Pleistoannelida, Sedentaria I. De Gruyter, Berlin, pp. 457 - 465. https: // doi. org / 10.1515 / 9783110291582 - 007","Laubier, L., Picard, C. & Ramos, J. (1974) Les Heterospionidae (Annelides Polychetes Sedentaires) de Mediterranee occidentale. Vie et Milieu, Series A, 23 (2), 243 - 254. [actual date of publication: Mar 1974] [https: // hal. sorbonne-universite. fr / hal- 02982257 / document]","Bochert, R. & Zettler, M. L. (2009) A new species of Heterospio (Polychaeta, Longosomatidae) from offshore Angola. Zoological Science, 26, 735 - 737. https: // doi. org / 10.2108 / zsj. 26.735","Borowski, C. (1994) New records of Longosomatidae (Heterospionidae) (Annelida, Polychaeta) from the abyssal Southeast Pacific, with the description of Heterospio peruana sp. n. and general remarks on the family. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 92 (Supplement 1), 129 - 144.","Parapar, J., Aguirrezabalaga, F. & Moreira, J. (2014) First record of Longosomatidae (Annelida: Polychaeta) from Iceland with a worldwide review of the family. Journal of Natural History, 48, (17 - 18), 983 - 998. https: // doi. org / 10.1080 / 00222933.859316","Blake, J. A. (2021 a) New species and records of Orbiniidae (Annelida, Polychaeta) from continental shelf and slope depths of the Western North Atlantic Ocean. Zootaxa, 4930 (1), 1 - 123. https: // doi. org / 10.11646 / zootaxa. 4630.1.1"]}

Heterospio africana new species Figures 26–27 urn:lsid:zoobank.org:act: 0BF6D8E4-55B9-4A24-BC45-A2A0D2585828 Material examined. East Africa, off Mozambique, International Indian Ocean Expedition, R / V Anton Bruun, Cruise 7, Sta. AB 372 H, coll. 19 Aug 1964, Olga Hartman, Campbell Grab, 24.900ºS, 34.923ºE, 55 m, sand and mud, holotype (LACM-AHF Poly 13288). Description. Holotype (LACM-AHF Poly 13288) complete, 16.6 mm long, 0.25 mm wide across thoracic setigers and 0.41 mm wide across abdominal setigers; with 27 setigers, including 9 thoracic, 14 abdominal, and 4 in posterior bulbous section. Body long, thin, with most abdominal setigers each about as long as entire thoracic region. Thoracic region generally dorso-ventrally flattened, cylindrical in cross section. Dorsal surface of thoracic region with narrow dorsal ridge extending from peristomium to end of setiger 7 (Fig. 26A); venter relatively smooth with no ventral ridge or groove (Fig. 26B). Color in alcohol opaque white. Pre-setiger region triangular as long as first three setigers (Fig. 26A). Prostomium conical, smoothly rounded on tip (Fig. 26A–B); eyes absent; nuchal organs narrow grooves on posterior lateral margins at border with peristomium (Fig. 26A). Peristomium divided into the two rings by dorsolateral grooves from which dorsal tentacles arise in other species, but tentacles not attached in holotype. First ring very narrow; second ring as large as following setiger 1 (Fig. 26A). Peristomium interrupted dorsally by prominent dorsal crest on setiger 1 and continuing posteriorly as a narrow dorsal ridge to near end of setiger 7 (Fig. 26A). Ventrally, peristomium smooth, with oral opening a transverse slit bordered anteriorly by four lobes and posteriorly by a single curved lower lip (Fig. 26B); proboscis not observed. Branchiae present on setigers 2–6 (Fig. 26A), with no evidence of scars or stubs on setiger 7 or later even when stained with MG or Shirlastain A; branchiae when present long, thin, rounded in cross section, tapering to rounded tip; branchiae with narrow ciliated groove; internal blood vessel extends along entire length. All parapodia of thoracic and abdominal setigers biramous with setal fascicles arising from near anterior border of each segment; at least three of four setigers of posterior region biramous; last likely only with notosetae. Thoracic region with eight short setigers, each about twice as wide as long; with setiger 8 slightly longer, about half again as long as setiger 7; setiger 9 first elongated setiger, about 2.5 times longer than setiger 7. Setiger 10 first abdominal setiger, about as long as setigers 1–8 combined; subsequent abdominal setigers 11–23 each of a similar length, about as long as entire thoracic region (Fig. 27A). Thoracic notopodia through setiger 9 with notosetae arising as tight fascicles from simple grooves or notches; neuropodia of setigers 1–8 with a short postsetal lamella (Fig. 26B). Abdominal parapodia from setiger 10 with parapodia as narrow ridges or rows encircling each segment, with narrow dorsal, ventral, and lateral gaps separating noto- and neurosetae (Fig. 26A). All thoracic noto- and neuropodia of setigers 1–9 with numerous long capillaries in tightly packed, spreading fascicles, of 25 to 30 or more long capillaries (Figs. 26A, 27A–B). Abdominal setigers 10–11 with two rows of capillaries, mostly encircling body; capillaries of first row thicker than thin capillaries of second row (Fig. 26D). Setigers 12–13 with subuluncini (Fig. 26C) and a few acicular spines in first row and thin capillaries in second row. Setigers 14–20 with acicular spines in first row (Fig. 26E) and thin capillaries in second row; rarely with aristate spines among the acicular spines. Acicular spines weakly curved, narrowing to narrow blunted tip (Figs. 26E, 27F– G). Far posterior setigers 21–23 with subuluncini replacing acicular spines in first row and thin capillaries in second row. Posterior bulbous section with four parapodia each with distinctly curved hooks (Figs. 26F, 27D–E); first three of these setigers biramous with two hooks; fourth setiger with only a single notopodial hook. Posterior bulbous section as long as wide, heavily wrinkled, with parapodia best observed in anterior half (Fig. 27C); posterior half with large folds surrounding anal opening. Methyl Green staining. No pattern. Remarks. In Heterospio africana n. sp., the large peristomial crest continues along the surface of the first seven setigers as a narrow, but prominent mid-dorsal ridge. Such a prominent ridge has not been observed in other species. In addition, while H. africana n. sp. is one of several species to have setiger 9 as the first elongate setiger, about 2.5 times the length of setiger 8, it is the only species with branchiae limited to setigers 2–6. Species with branchiae from setiger 2–7 and a similarly long setiger 9 include H. guiana n. sp. and H. paulolanai n. sp.; however, both of these species lack a dorsal peristomial crest. Etymology. The species is named for its occurrence off the SE coast of Africa. Distribution. East Africa, off Mozambique, 55 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 53-56, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920

Genus Heterospio Ehlers, 1874 Type species: Heterospio longissima Ehlers, 1874, by monotypy. Synonym: Longosoma Hartman, 1944. Type species: Longosoma catalinensis Hartman, 1944, by monotypy. Generic Diagnosis. (emended): Body elongated, linear, divided into three regions: an anterior region with seven to nine short setigers, a median or abdominal region with greatly elongated segments, and a posterior bulbous region bearing three to five short segments. Prostomium narrow, conical, or broadly rounded to disk-like; nuchal organs narrow slits on posterior lateral margins. One pair of grooved peristomial dorsal tentacles, easily lost, arising from notches on dorsolateral surfaces of peristomium. Proboscis an eversible epithelial pouch. Anterior region with one to eight pairs of cirriform branchiae beginning on setiger 2, usually very long when present, arising above and near notopodia. Parapodia biramous with setal fascicles arising from near anterior margin of each segment. Anterior or thoracic region with simple capillaries in tightly defined fascicles, neuropodial acicular spines present or absent on setiger 1. Parapodia of abdominal segments with setae arranged in two elongate rows producing cinctures similar to those of some cirratulids. Abdominal setae include simple capillaries, acicular spines, aristate spines, and subuluncini. Posterior inflated section with acicular hooks. Remarks. The number of branchial pairs, location of the first elongated segment, and the nature and arrangement of setae along the body are the characters most often used to separate species in the genus. However, there have been differing approaches to identify where the abdominal or elongated segments first begin, and other characters have proven to be equally important. See Discussion at end of paper. The description of Heterospio longissima from off Ireland in 837 m by Ehlers (1874, 1875) was the first account of this unusual group of polychaetes. It was another 70 years before the second species, H. catalinensis (Hartman, 1944), (as Longosoma) was described from southern California followed by H. sinica Wu & Chen, 1960 from China, H. mediterranea Laubier et al., 1974 and H. reducta Laubier et al., 1974 from the Mediterranean Sea, and H. peruana Borowski, 1994 from off Peru in abyssal depths. The two most recently described species are H. angolana Bochert & Zettler, 2009 from West Africa, and H. indica Parapar et al., 2016 from the Arabian Sea off India. Blake & Maciolek (2019) listed these eight valid species of Heterospio but noted that additional species from various deep-water collections were known to them. In the present study, specimens have been accumulated from sites throughout the North Atlantic Ocean, Gulf of Mexico, off Brazil, California, SE Australia, New Zealand, the South China Sea, and the Indian Ocean. Most materials are from deep-water surveys. From these a total of 19 species have been identified, 15 new to science. The following species of Heterospio, grouped by geographic area, are identified and treated in this study: 1. Heterospio hartmanae new species 2. Heterospio aruba new species 3. Heterospio bathyala new species 4. Heterospio canariensis new species 5. Heterospio dibranchiata new species 6. Heterospio guiana new species 7. Heterospio cf. reducta Laubier, Picard & Ramos, 1974 8. Heterospio southwardorum new species 9. Heterospio paulolanai new species 10. Heterospio alata new species 11. Heterospio bidentata new species 12. Heterospio brunei new species 13. Heterospio catalinensis (Hartman, 1944 ) 14. Heterospio ehlersi new species 15. Heterospio knoxi new species 16. Heterospio peruana Borowski, 1994 17. Heterospio africana new species 18. Heterospio antonbruunae new species 19. Heterospio indica Parapar, Vijapure, Moreira & Sukumaran, 2016, Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 6-7, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Ehlers, E. (1874) Annulata nova vel minus cognita in Expeditione \" Porcupine \" capta. The Annals and Magazine of Natural history, Series 4, 13, 292 - 298. [https: // www. biodiversitylibrary. org / page / 24342680]","Hartman, O. (1944) Polychaetous annelids. Part VI. Paraonidae, Magelonidae, Longosomidae, Ctenodrilidae, and Sabellariidae. Allan Hancock Pacific Expeditions, 10 (3), 311 - 481, pls. 27 - 42. [https: // www. biodiversitylibrary. org / page / 4680266]","Ehlers, E. (1875) Beitrage zur Kenntniss der Verticalverbreitung der Borstenwurmer im Meere. Zeitschrift fur wissenschaftliche Zoologie, 25, 1 - 102, 4 pls. [https: // www. biodiversitylibrary. org / page / 45143254]","Laubier, L., Picard, C. & Ramos, J. (1974) Les Heterospionidae (Annelides Polychetes Sedentaires) de Mediterranee occidentale. Vie et Milieu, Series A, 23 (2), 243 - 254. [actual date of publication: Mar 1974] [https: // hal. sorbonne-universite. fr / hal- 02982257 / document]","Borowski, C. (1994) New records of Longosomatidae (Heterospionidae) (Annelida, Polychaeta) from the abyssal Southeast Pacific, with the description of Heterospio peruana sp. n. and general remarks on the family. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 92 (Supplement 1), 129 - 144.","Bochert, R. & Zettler, M. L. (2009) A new species of Heterospio (Polychaeta, Longosomatidae) from offshore Angola. Zoological Science, 26, 735 - 737. https: // doi. org / 10.2108 / zsj. 26.735","Parapar, J., Vijapure, T., Moreira, J. Sukumaran, S. (2016) A new species of Heterospio (Annelida, Longosomatidae) from the Indian Ocean. European Journal of Taxonomy, 220, 1 - 17. https: // doi. org / 10.5852 / ejt. 2016.220","Blake, J. A. & Maciolek, N. J. (2019) 7.3. 1.9. Longosomatidae Hartman, 1944. In: Purschke, G., B ˆ ggemann, M. & Westheide, W. (Eds.), Handbook of Zoology. Annelida. Vol. 1. Annelida Basal groups and Pleistoannelida, Sedentaria I. De Gruyter, Berlin, pp. 457 - 465. https: // doi. org / 10.1515 / 9783110291582 - 007"]}

Comments on Heterospio longissima Ehlers, 1874 The original account of Heterospio longissima . The genus Heterospio was first described by Ehlers (1874, 1875) based on a single anterior fragment collected off SW Ireland (51.017°N, 11.35°W) in 458 fathoms (837 m). Ehlers (1874) introduced the genus and species names briefly in Latin as part of a summary of new or little known polychaetes collected as part of the Porcupine Expedition. The full description, however, with illustrations was not published until a year later (Ehlers 1875). Ehlers placed his new genus in the Spionidae and named the new species H. longissima. He provided relevant details and an illustration of the anterior end. Based on Ehlers’ original description and figures (Ehlers 1875: Pl. 25, figs. 10–11) and our interpretation of his illustrations (Fig. 1), the type species can be characterized as follows: Description of Heterospio longissima Ehlers, 1874 . A 12-setiger anterior fragment, 25 mm long, 0.5–0.8 mm wide. Body with a short anterior or thoracic region about 2 mm long with prostomium, peristomium, and eight short setigers each wider than long (Fig. 1A–B); these followed by setiger 9, the first elongate segment, about as long as first 8 setigers combined (Fig. 1A–B). Branchiae present on setigers 2–9 posterior to setal fascicles, one long branchia on setiger 4, with rest mostly stubs or scars. Setigers 10–12 (abdominal) each long, with setiger 10 being 4.5 times as long as setigers 1–9 combined; last two segments each about 8 times as long as anterior segments. Prostomium short, broadly rounded on anterior margin (Fig. 1A), flattened dorso-ventrally. Peristomium a single ring without dorsal crest; mouth surrounded by lobes (Fig. 1A). Setae arise from anterior border of each segment (Fig. 1A–B); setigers 1–9 with setae in discrete, narrow, fan-shaped fascicles; setigers 10–12 with setae arising in rows producing broad transverse fascicles along anterior and lateral margins, with dorsal, ventral, and lateral gaps; all setae capillaries. Presence of other types of setae not observed on available segments. Remarks. This description is based on Ehlers’ (1874, 1875) text and illustrations and is the best we can present based on the limited available information. Ehlers (1874, 1875) states that the mouth has two transverse lobes on the anterior lip but his Pl. 25, fig. 11 suggests that additional lateral lobes may also be present. Based on information published by Laubier et al. (1974) and Borowski (1994) as well as correspondence by the first author with the late Drs. M.E. Petersen and G. Hartmann-Schr̂der (in litt.), Ehlers’ type-specimen is not present in the Museum of Natural History, London, or the Zoological Museum of Hamburg and is presumed lost. It is noteworthy that despite additional surveys and collections from near the type locality off SW Ireland, no additional specimens that agree with Ehlers’ (1874, 1875) description have been found. Although Amoureux (1982) reported specimens that he identified as H. longissima, he did not describe them. Conversely, specimens that agree well with a Mediterranean species, H. reducta, have been identified from the same general area and depths (Amoureux 1982; Parapar et al. 2014; this study). Hartman’s (1965) concept of H. longissima . Hartman (1965), as part of a monograph on deep-water polychaetes from the North Atlantic Basin collected by H.L. Sanders and R. R. Hessler, described and illustrated specimens she assigned to Heterospio longissima. As noted in the Introduction, Hartman’s concept of the species has been used by many investigators to characterize the type species. Laubier et al. (1974), as part of a paper describing two new species of Heterospio from the Mediterranean Sea, examined several specimens of H. longissima from the Sanders/Hessler collections loaned to them by Dr. Hartman but did not specify which stations they were from. This omission is problematic because there are two distinct species in Hartman’s material (see below). Laubier et al. (1974) determined that Hartman’s concept of H. longissima differed from Ehlers’ (1874, 1875) original description in that setiger 9, the first elongate segment, was only about 2.5 times longer than setiger 8 instead of setiger 9 being as long as the preceding eight setigers. However, there are additional differences between Ehlers’ original description, brief as it is, and Hartman’s version, which itself contains several errors. One is that Ehlers found only capillary setae on his 12-setiger specimen, whereas Hartman reported acicular spines. Nevertheless, the morphological concept presented by Hartman (1965) and slightly modified by Laubier et al. (1974) has been perpetuated and modified in several subsequent studies as “ H. longissima sensu Hartman ” (Laubier et al. 1974; Borowski 1994; Bochert & Zettler 2009; Parapar et al. 2014, 2016). It is generally assumed, although not specifically stated by these authors, that Hartman’s (1965) concept of H. longissima represents the actual morphology of Ehlers’ species. However, based on an examination of Hartman’s original materials, it is clear that the description presented by Hartman (1965) is incorrect in several aspects. There are major differences between Hartman’s (1965) description of the specimens and our observations of the same material. The most striking differences are: (1) The branchial distribution reported and illustrated (Hartman 1965: Pl. 30, fig. f) for a specimen from R/V Atlantis Sta. II-2 indicates long filamentous branchiae on setigers 2–9, whereas the present observations of more than 50 specimens, including five from the same sample (R/V Atlantis II-2), consistently have branchiae on setigers 2–5 with no evidence of scars or stubs of additional branchiae on more posterior setigers on any specimen. (2) The prostomium on Hartman’s Pl. 30 fig. f is shown as narrow and pointed; whereas none of the specimens examined from that station or others have such a prostomium. The conical prostomium, while narrowing anteriorly, definitely has a rounded, not pointed, tip. (3) Hartman’s Pl. 30, fig. f illustrates two dorsal tentacles arising from the peristomium. In the present study, no specimens from the Sanders/Hessler’s collections had attached dorsal tentacles; however, one small specimen from ACSAR Sta. 16 had one dorsal tentacle arising from the right side of the peristomium. Hartman (1965:163) does indicate in the text that “several long grooved palpi are present in the sample”. These were probably added to the illustration. (4) The main illustration of the anterior end, Pl. 30, fig. f, does not correctly depict the relationship of the emergence of the setal fascicles on the segments of this species or Heterospio in general. The parapodia are depicted with the setal fascicles emerging from the middle of each segment rather than on or near the anterior margin, a character that defines the genus (and family). This incorrect depiction of the origin of the setal fascicles also includes an additional segmental furrow suggesting that an additional setigerous segment is present due to its placement after the eighth pair of branchiae. This error was pointed out by Laubier et al. (1974) who diagramed the correct segmental sequence. However, these authors did not comment on the number or placement of branchiae on the specimens they examined. Contributing to the confusion is that Hartman (1965) wrote only of acicular spines and capillaries in abdominal parapodia and did not indicate that spines having an arista or other type of terminal extension were present. Borowski (1994) specifically stated that H. longissima sensu Hartman did not have aristate setae but mistakenly reported subuluncini in his Table 2 when referring to Hartman (1965). Parapar et al. (2014) evidently followed Borowski’s table and included subuluncini in their description of H. longissima sensu Hartman based on specimens from off Iceland in bathyal depths (784–834 m). The specimens from Hartman’s collection reported here as H. hartmanae n. sp. are from lower continental slope and abyssal depths (2470–4950 m) and have only acicular spines and capillaries in the abdominal cinctures from setiger 10. The specimens reported by Parapar et al. (2014) most likely represent an undescribed species. There is no obvious reason why the account of H. longissima by Hartman (1965) contains so many errors. However, the collection date of the last sample used in the study was April 1963, leaving only two years between the final collection date and the release of the monograph in April 1965 to process over 27,000 specimens and identify, describe, and illustrate more than 265 species, 70 of which were new to science. Further, four different illustrators were employed to assist Dr. Hartman on the project, including at least two technical assistants, perhaps students, one of whom is acknowledged as preparing Plate 30. It seems likely that morphological details in the illustrations and text were not rechecked against the actual specimens, or the text was edited after the illustrations were prepared and details were not confirmed. Part of the problem may also be that the Sanders/Hessler collections examined by Hartman (1965) were from different locations. The main collections along the Gay-Head-Bermuda transect from off New England to Bermuda were mostly from abyssal depths and included the species with branchiae on setigers 2–5 described here as H. hartmanae n. sp. These collections differ from the original account as noted above. However, specimens were also collected from ca. 550 m off Suriname (then Dutch Guiana) and were also listed as H. longissima by Hartman (1965). These, however, are a different species, here described as H. guiana n. sp. These latter specimens agree more closely with Hartman’s Pl. 30, fig. f in that some long branchiae were present and branchiae or stubs were found from setigers 2–8. It seems possible that Hartman and/or her illustrator may have consulted specimens from both areas and assumed that observed differences were variations of the same species. In those days, Heterospio was rare, nothing was known about morphological variability, and many polychaete species were often assumed to have global distributions. Since the first two described species of Heterospio, Ehlers’ H. longissima and Hartman’s H. catalinensis had branchiae on setigers 2–9 and we recently learned that specimens from New Zealand that the late Dr. George Knox carried with him during a visit with Dr. Hartman in 1959 also had branchiae on setigers 2–9 (see Heterospio knoxi n. sp. below), it might be that Dr. Hartman assumed that this was typical for the genus. A final issue is that Ehlers’s specimen came from an upper continental slope or bathyal site of about 837 m, whereas Hartman’s North Atlantic collections were largely from abyssal depths of 3000 m and greater. In our experience, upper slope or bathyal species rarely range into abyssal depths. Summary. Ehlers’ type-specimen is apparently lost and no specimens having the same morphology described and depicted by Ehlers (1875) have been reported from the type-locality. Hartman’s (1965) concept of H. longissima is shown in the present study to represent two different species, neither of which agrees with Ehlers’ original account., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 7-10, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Ehlers, E. (1874) Annulata nova vel minus cognita in Expeditione \" Porcupine \" capta. The Annals and Magazine of Natural history, Series 4, 13, 292 - 298. [https: // www. biodiversitylibrary. org / page / 24342680]","Ehlers, E. (1875) Beitrage zur Kenntniss der Verticalverbreitung der Borstenwurmer im Meere. Zeitschrift fur wissenschaftliche Zoologie, 25, 1 - 102, 4 pls. [https: // www. biodiversitylibrary. org / page / 45143254]","Laubier, L., Picard, C. & Ramos, J. (1974) Les Heterospionidae (Annelides Polychetes Sedentaires) de Mediterranee occidentale. Vie et Milieu, Series A, 23 (2), 243 - 254. [actual date of publication: Mar 1974] [https: // hal. sorbonne-universite. fr / hal- 02982257 / document]","Borowski, C. (1994) New records of Longosomatidae (Heterospionidae) (Annelida, Polychaeta) from the abyssal Southeast Pacific, with the description of Heterospio peruana sp. n. and general remarks on the family. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 92 (Supplement 1), 129 - 144.","Amoureux, L. (1982) Annelides polychetes recueillies sur le pente continentale de la Bretagne a l'Irlande, campagne 1973 de la \" THALASSA \" (suite et fin) avec la description de quatre especes nouvelles pour la science. II. Inventaire taxonomique annote de toutes les polychetes sedentaires. Cahiers de Biologie Marine, 23, 179 - 214. https: // doi. org / 10.21411 / cbm. a. 5 e 35 f 37 e","Parapar, J., Aguirrezabalaga, F. & Moreira, J. (2014) First record of Longosomatidae (Annelida: Polychaeta) from Iceland with a worldwide review of the family. Journal of Natural History, 48, (17 - 18), 983 - 998. https: // doi. org / 10.1080 / 00222933.859316","Hartman, O. (1965) Deep-water benthic polychaetous annelids off New England to Bermuda and other North Atlantic areas. Allan Hancock Foundation Occasional Paper, 28, 1 - 378, 52 pls. [http: // digitallibrary. usc. edu / digital / collection / p 15799 coll 82 / id / 20299]","Bochert, R. & Zettler, M. L. (2009) A new species of Heterospio (Polychaeta, Longosomatidae) from offshore Angola. Zoological Science, 26, 735 - 737. https: // doi. org / 10.2108 / zsj. 26.735","Parapar, J., Vijapure, T., Moreira, J. Sukumaran, S. (2016) A new species of Heterospio (Annelida, Longosomatidae) from the Indian Ocean. European Journal of Taxonomy, 220, 1 - 17. https: // doi. org / 10.5852 / ejt. 2016.220"]}

Heterospio canariensis new species Figure 7 urn:lsid:zoobank.org:act: 4323AD1B-C80B-49D5-8418-CBDD9B5A7CED Material examined. (9 specimens) Eastern North Atlantic Ocean, off Canary Islands, SE of Gran Canaria Island, coll. J. Allen, RRS Discovery, Cruise 21, Sta. 6711, 19 Mar 1968, EBS, 27.248°N, 15.605°W, 2988 m, holotype (LACM-AHF Poly 13266); 4 paratypes plus middle and post. fragments (LACM-AHF Poly 13267); Sta. 6709, 18 Mar 1968, EBS, 27.537°N, 15.427°W, 2351 m, 3 paratypes (LACM-AHF Poly 13264); Sta. 6710, 19 Mar 1968, EBS, 27.395N, 15.66°W, 2670 m, 1 paratype plus posterior fragments (LACM-AHF Poly 13265). Description. An elongate, threadlike species; all specimens incomplete, material includes anterior fragments with 12–13 setigers, abdominal fragments, and posterior fragments with bulbous posterior ends containing at least three setigers. Holotype (LACM-AHF Poly 13266) an anterior fragment with 13 setigers, 16.6 mm long, 0.36 mm wide across thorax and 0.38 mm wide across abdominal segments. Paratype (LACM-AHF Poly 13267) with 12 setigers, 12.4 mm long, 0.41 mm wide across thorax and 0.21 mm wide across abdominal segments. Dorsal surface of thoracic region with parapodia weakly elevated producing flattened channel along first seven setigers (Fig. 7A); following abdominal segments with relatively smooth surface interrupted by numerous transverse muscle bands. Ventral surface with mid-ventral ridge extending from peristomium to about setiger 6 (Fig. 7B), thereafter ventral surface relatively smooth, similar to that of dorsum. Color in alcohol light tan. Pre-setiger region about as long as first three thoracic setigers (Fig. 7A–B). Prostomium rhomboid-shape in dorsal view, widest medially, anteriorly tapering to broadly rounded apex, narrowing posteriorly, continuing as dorsal crest or ridge over peristomium to middle of setiger 3 (Fig. 7A); eyespots absent; nuchal organs distinct slits on posterior lateral margins anterior to first peristomial ring; dorsal surface with numerous small lumps extending over dorsal surface, not as obvious on ventral surface (Fig. 7A); ventrally prostomium broadly rounded anteriorly, merging posteriorly with upper lip of mouth (Fig. 7B). Peristomium with two rings; anterior ring unusually narrow (Fig. 7A), ventrally forming anterior lip of mouth (Fig. 7B); posterior ring as large as subsequent parapodia, interrupted dorsally by dorsal crest (Fig. 7A) and ventrally by posterior lip of mouth and ventral ridge (Fig. 7B). Mouth opening a transverse slit with about six large lobes on anterior lip and smaller indistinct lobes on posterior lip that merge with mid-ventral ridge (Fig. 7B). Proboscis partially everted on some specimens as simple rounded lobe. Dorsal tentacles not present on any specimen, but scars evident mid-dorsally in notches between two peristomial rings. Branchiae limited to setiger 1 on all specimens examined (Fig. 7A); branchiae short, thick, apparently broken or regenerating. All parapodia biramous with setal fascicles arising from near anterior edge of segment. Thoracic region of all specimens with eight short setigers, twice as wide as long (Fig. 7A); setiger 9 elongate, about as long as thoracic setigers 5–8 combined (Fig. 7A). All thoracic setigers slightly flattened dorsally with parapodia inflated and elevated over dorsum, bearing setae in tight fascicles. Abdominal setigers from setiger 10 rounded in cross section, bearing setae in transverse rows encircling each segment similar to cinctures of some cirratulid polychaetes (Fig. 7A). Abdominal parapodia from setiger 10 narrow elongate lobes, noto- and neuropodia with distinct dorsal and ventral gaps between setal fascicles; lateral gaps between noto- and neuropodia narrower. All thoracic notopodia of setigers1–9 with 10–15 long capillaries in spreading fascicles; capillaries of neuropodia more numerous with up to 20–25 setae arranged in tight, dense fascicle. Noto- and neuropodia of setigers 10–13 with both capillaries and acicular spines in two transverse rows forming cinctures similar to those of some cirratulid polychaetes; cinctures partial on setiger 10, fully developed on setigers 11–13. Spines present in anterior or first row of setae and more numerous capillaries in posterior row. Acicular spines thickened, tapering to narrow pointed tip (Fig. 7D), aristate spines not observed; capillaries thin, narrowing to long fine tip (Fig. 7E). Far posterior bulbous section oval-shaped, with dorsal groove and terminal anal opening; with three parapodia, each bearing 1–2 hooked spines in each ramus. Each spine short, with curved with narrow blunted tip (Fig. 7F). Methyl Green staining. Prostomium and both peristomial rings staining intensely with unstained grooves between, producing distinct pattern; laterally, first eight setigers staining intensely between parapodia, also producing pattern; areas where setae emerge not staining. Rest of body not retaining stain, no pattern. Remarks. Heterospio canariensis n. sp. is characterized by having: (1) two peristomial rings where the first is narrow and ventrally forms the anterior lip of the mouth, (2) a dorsal crest that extends from the prostomium posteriorly to about setiger 2, (3) a ventral crest or ridge that extends from the posterior lip of the mouth to about setiger 6, (4) only a single pair of branchiae (setiger 2), (5) setiger 9 is the first long setiger and is about as long as the preceding setigers 5–8, (6) acicular spines are simple and first present from setiger 10, and (7) the posterior bulbous section has at least three parapodia each with 1–2 curved hooked spines. No other species of Heterospio has this combination of characters. Etymology. The epithet is derived from the type locality off the Canary Islands. Distribution. Eastern North Atlantic Ocean, off Canary Islands, 2351–2988 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 21-23, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920

Family Longosomatidae Hartman, 1944 Type genus: Heterospio Ehlers, 1874. Synonym: Heterospionidae Hartman, 1963. Fide Petersen 1992: 80, Borowski 1994. Generic Diagnosis: Same as genus Heterospio (see below). Remarks: Longosomatids are easily recognized by the unusually long segments of the middle body region; this character was considered a synapomorphy by Fauchald & Rouse (1997). Another unusual aspect of longosomatid segmentation is that the setal fascicles emerge on the anterior end of each of the short anterior and elongated middle segments, rather than from the middle of the segment as is typical of most polychaetes. The enlarged bulbous posterior end with pairs of curved spines likely serves as an anchor, which probably accounts for most specimens being fragmented when removed from sediment. Ehlers (1874, 1875) originally placed his new genus in the Spionidae and even after being referred to a new family (Hartman 1944, 1965) it was considered a spioniform (Fauchald 1977, Rouse & Fauchald 1997, Blake & Arnofsky 1999; Read & Fauchald 2022). However, recent interpretation of morphology and newly obtained molecular data supports a close affiliation of Longosomatidae with Cirratulidae (Blake & Maciolek 2019; Rouse et al. 2022); this position was also taken by Wilson (2000) and Grosse et al. (2021). Longosomatids are similar to cirratulids in having long filamentous branchiae that differ from the broad flattened branchiae of spionids, a pair of long dorsal tentacles and in most species, the arrangement of abdominal setae into cinctures that mostly surround the body., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on page 6, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Hartman, O. (1944) Polychaetous annelids. Part VI. Paraonidae, Magelonidae, Longosomidae, Ctenodrilidae, and Sabellariidae. Allan Hancock Pacific Expeditions, 10 (3), 311 - 481, pls. 27 - 42. [https: // www. biodiversitylibrary. org / page / 4680266]","Ehlers, E. (1874) Annulata nova vel minus cognita in Expeditione \" Porcupine \" capta. The Annals and Magazine of Natural history, Series 4, 13, 292 - 298. [https: // www. biodiversitylibrary. org / page / 24342680]","Petersen, M. E. (1992) Provisional review of the Cirratulidae from the Faroes, with comments on some other groups (Annelida, Polychaeta). Nordurlandahusid arsrit, Yearbook for 1991 - 1992, 79 - 80.","Borowski, C. (1994) New records of Longosomatidae (Heterospionidae) (Annelida, Polychaeta) from the abyssal Southeast Pacific, with the description of Heterospio peruana sp. n. and general remarks on the family. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 92 (Supplement 1), 129 - 144.","Fauchald, K. & Rouse, G. D. (1997) Polychaete systematics: Past and Present. Zoological Scripta, 26 (2), 71 - 138. https: // doi. org / 10.1111 / j. 1463 - 6409.1997. tb 00411. x","Ehlers, E. (1875) Beitrage zur Kenntniss der Verticalverbreitung der Borstenwurmer im Meere. Zeitschrift fur wissenschaftliche Zoologie, 25, 1 - 102, 4 pls. [https: // www. biodiversitylibrary. org / page / 45143254]","Hartman, O. (1965) Deep-water benthic polychaetous annelids off New England to Bermuda and other North Atlantic areas. Allan Hancock Foundation Occasional Paper, 28, 1 - 378, 52 pls. [http: // digitallibrary. usc. edu / digital / collection / p 15799 coll 82 / id / 20299]","Fauchald, K. (1977) The Polychaete Worms: Definitions and Keys to the Orders, Families, and Genera. Natural History Museum of Los Angeles County Science Series, 28, 1 - 188. [https: // repository. si. edu / handle / 10088 / 3435]","Blake, J. A. & Arnofsky, P. L. (1999) Reproduction and development of the spioniform Polychaeta with application to systematics and phylogeny. Hydrobiologia, 402, 57 - 106. https: // doi. org / 10.1023 / A: 1003784324125","Read, G. & Fauchald, K. (Ed.) (2022) World Polychaeta Database. Heterospio Ehlers, 1874. World Register of Marine Species. Available from: https: // www. marinespecies. org / aphia. php? p = taxdetails & id = 129325 (accessed 23 May 2022)","Blake, J. A. & Maciolek, N. J. (2019) 7.3. 1.9. Longosomatidae Hartman, 1944. In: Purschke, G., B ˆ ggemann, M. & Westheide, W. (Eds.), Handbook of Zoology. Annelida. Vol. 1. Annelida Basal groups and Pleistoannelida, Sedentaria I. De Gruyter, Berlin, pp. 457 - 465. https: // doi. org / 10.1515 / 9783110291582 - 007","Rouse, G. W, Pleijel, F. & Tilic, E. (2022) Annelida. Oxford University Press, Oxford, xiii + 418 pp. https: // doi. org / 1093 / oso / 9780199692309.001.0001","Wilson, R. (2000) Family Longosomatidae. In: Beesley, P. L., Ross, G. J. B. & Glasby, C. J. (Eds.), Polychaetes and allies: the Southern synthesis. CSIRO Publishing, Melbourne, pp. 1 - 193.","Grosse, M., Zhadan, A., Langeneck, J., Fiege, D. & Martinez, A. (2021) Still Digging: Advances and Perspectives in the Study of the Diversity of Several Sedentarian Annelid Families. Diversity, 13, 132. https: // doi. org / 10.3390 / d 13030132"]}

Heterospio hartmanae new species Figures 2–3 urn:lsid:zoobank.org:act: 6F790C3E-6DD7-473B-89C2-AD6A690AA95F Heterospio longissima: Hartman 1965: 163–164, Plate 30, figs. F–H; Hartman & Fauchald 1971: 108–109 (in part). Not Ehlers 1874, 1875. Heterospio cf. longissima: Blake & Grassle 1994: 861 (in part); Hilbig 1994: 941 (in part). Not Ehlers 1874, 1875. Not H. longissima sensu Hartman: Laubier et al. 1974; Borowski 1994; Parapar et al. 2014, 2016. Material examined. (55 specimens in addition to many middle and posterior fragments) Western North Atlantic Ocean. Off New England, Gay Head Bermuda Transect, coll. H. L. Sanders and R.R Hessler. R/V Atlantis Cruise 264, Sta. II-2, 24 May 1961, AD, 38.083°N, 69.6W, 3752 m, holotype (LACM-AHF Poly 13270); 4 paratypes and post. ends, (LACM-AHF Poly 13271); Sta. HH-3, 21 May 1961, AD, 38.783°N, 70.133°W, 2900 m (3, small, LACM-AHF Poly 13272); Sta. II-1, 22 May 1961, AD, 37.983N, 69.533W, 3742 m, 1 paratype and 2 post. ends (LACM-AHF Poly 13273); R/V Atlantis Cruise 273, Sta. JJ-1, 02 Oct 1961, AD, 37.45°N, 68.683W, 4436 m (4, dry, LACM-AHF Poly 13274); Sta. GH-4, 03 Oct 1961, AD, 39.8°N, 70.95W, 2470 m (1, small, LACM-AHF Poly 13275); R/V Atlantis Cruise 277, Sta. JJ-3, 25 May 1962, AD, 37.217°N, 68.66°W, 4540 m (1, LACM-AHF Poly 13276); Sta. NN-1, 29 May 1962, AD, 33.942°N, 66.567°W, 4950 m (1 juv, LACM-AHF Poly 13277); R/V Atlantis II Cruise 12, Sta. 65, AD, 21 Aug 1964, 38.78°N, 70.113°W, 2891 m (3 post. ends, LACM-AHF Poly 13278); Sta. 71, 24 Aug 1964, AD, 38.133°N, 71.792°W, 2946 m, 10 paratypes and 9 post. ends and fragments., (LACM-AHF Poly 13279); Sta. 72, 24 Aug 1965, EBS, 38.267°N, 71.783°W, 2864 m (1, ant., LACM-AHF Poly 13280); R/V Chain, Cruise 50, Sta. Ch- 85, 05 Jul 1965, EBS, 37.987°N, 69.437W, 3834 m (2, LACM-AHF Poly 13281); R/V Atlantis II, Cruise 17, Sta. 95, EBS, 17 Dec 1965, 38.55°N, 68.533°W, 3573 m, 11 paratypes, 3 post. ends (LACM-AHF Poly 13282). — Off New Jersey and Delaware, U.S. Mid-Atlantic ACSAR Program, coll. R. Petrecca, Chief Scientist. Sta. 12, Cruise Mid-1, Rep. 2, 07 May 1984, BC, 38.489°N, 72.704°W, 2501 m, (1, USNM 1673091); Rep. 3, 07 May 1984, BC, 38.489°N, 72.704°W, 2500 m (1 juv, USNM 1673092). — Off Cape Fear, North Carolina, U.S. South Atlantic ACSAR Program, coll. J.A. Blake, Chief Scientist. Sta. 13, Cruise SA-4, Rep. 1, 21 May 1985, BC, 32.92°N, 73.83°W, 3015 m (1 post. end, USNM 1673093); Cruise SA-5, Rep. 1, 21 Sep 1985, BC, 32.921°N, 75.833°W, 3006 m (2, USNM 1673094); Rep. 2, 21 Sep 1985, BC, 32.919°N, 75.831° W, 3009 m (1, USNM 1673095); Cruise SA-6, Rep. 2, 20 Nov 1985, BC, 32.92°N, 75.837°W, 3002 m (1, USNM 1673096); Rep. 3, 21 Nov 1985, BC, 32.921°N, 75.835°W, 3006 m (1, USNM 1673097). — Off Charleston, South Carolina, coll. J.A. Blake, Chief Scientist. Sta. 16, Cruise SA-5, Rep. 1, 14 Sep 1985, 31.587°N, 75.173°W, 3009 m (1, USNM 1673098); Rep. 2, 16 Sep 1985, BC, 31.586′N, 75.171°W, 3011 m (2, USNM 1673099); Cruise SA-6, Rep. 2, BC, 20 Nov 1985, 31.585°N, 75.172°W, 3009 m (1, USNM 1673100); Rep. 3, 20 Nov 1985, BC, 31.586°N, 75.17° W, 3012 m (1, USNM 1673101). Description. Body long, narrow, threadlike (Fig. 2A–C), divided into an anterior thoracic region with crowded, slightly flattened segments, abdominal region with elongate cylindrical segments, and posterior region terminating in a bulbous pre-pygidial region bearing hooked spines. All larger specimens fragmented: largest holotype (LACM AHF-Poly 13270) with 13 setigers, 14.1 mm long, 0.4 mm wide across anterior setigers; paratype (LACM AHFPoly 13273) with 12 setigers, 14.9 mm long, 0.2 mm wide across anterior setigers. Only complete specimen (USNM 1673091) smaller, slender, with nine thoracic setigers, 15 abdominal setigers, and three setigers in posterior bulbous section for a total of 27 setigerous segments, this specimen 9.45 mm long, and 0.11 mm wide across thoracic segments (Fig. 2A–C). Color in alcohol opaque white to light tan; pigment entirely absent. Pre-setiger region short, about as long as first 3 or 3.5 thoracic segments (Figs. 2D–E; 3A–C). Prostomium roughly rhomboid-shaped, tapering anteriorly from wide middle section to narrow, rounded tip; posteriorly narrowing, encompassed by first peristomial ring (Figs. 2D–E, 3A–C); eyespots absent; nuchal organs narrow slits on posterior lateral margins (Fig. 3A). Peristomium with two rings, both prominent dorsally and laterally; first ring surrounding prostomium dorsally like a yoke, continuing laterally but not onto ventral surface; second ring a large achaetous segment interrupted dorsally by posterior extension of prostomium and complete ventrally, encompassing mouth (Fig. 3A–C). Mouth a transverse opening with anterior lip formed by 7–8 short lobes and posteriorly by 3–4 narrow lobes (Fig. 3B); pharynx everted on some specimens, short, rounded sac-like. A single dorsal tentacle observed on right side of one small specimen (USNM 1673098); this tentacle long, thickened in middle, arising from groove between anterior and posterior peristomial rings, subsequently detached during examination. Branchiae present on setigers 2–5 (Fig. 3A, C) on all specimens examined except juveniles; most branchiae short, stubby, a few longer ones basally thick, tapering to rounded tip; prominent stubs or branchial scars typically present if individual branchiae not evident; no evidence of branchiae or scars after setiger 5. Smallest juveniles with branchiae on setigers 2–3. Thoracic region consisting of eight short setigers, each about as wide as long, and a ninth transitional setiger about 2.5 times longer than setiger 8 (Figs. 2D–E, 3A–C). All thoracic setigers slightly flattened dorsally with parapodia weakly inflated and elevated over dorsum; similarly inflated ventrally.Abdominal setigers elongated from setiger 10, about 20–25 times longer than short thoracic setigers; setigers 10–24 elongate on complete specimen (USNM 1673091) and 10–14 on larger anterior fragments. All parapodia biramous with setal fascicles arising from anterior edge of segment, lateral and dorsal gaps between setal fascicles defining noto- and neuropodia. All thoracic noto- and neuropodia of setigers 1–9 with 12–15 long capillaries in spreading fascicles; abdominal setae from setiger 10 arranged in two rows producing cirratulidlike cinctures with numerous (25+) acicular spines in both noto- and neuropodia on each side, thus 50–60 spines on each side or 100–120 per segment; spines in anterior row accompanied by 25–30 or more thin capillaries in posterior row. Abdominal acicular spines with thick, weakly curved shaft tapering to narrow tip (Figs. 2F–G, 3F); aristate setae not present. Spines present on all abdominal setigers except last 3–4 posterior segments where setae all capillaries; complete 27-setiger specimen (USNM 1673091) with spines absent on setigers 22–24. Far posterior bulbous section with at least 2–3 parapodia each bearing two distinctly separated acicular spines in each ramus (Fig. 3D). Each spine yellow, curved, with blunt tip (Figs. 2C [inset], 3E). Methyl Green staining. Prostomium and peristomium stain intensely; segmental bands most evident ventrally. Remarks. The description of Heterospio hartmanae n. sp. presented here is based on the original materials collected from off New England to Bermuda by the late Drs. H.L. Sanders and R.R. Hessler and identified and reported as H. longissima Ehlers, 1874 by Hartman (1965) and Hartman & Fauchald (1971). A few additional specimens collected as part the U.S. ACSAR program off the Carolinas and off Delaware and New Jersey are also included. The species occurs in lower continental slope and abyssal depths from about 2500–4950 m. As detailed above in the previous section on Heterospio longissima, Hartman’s (1965) version, which has been followed by recent investigators as representative of the type-species, has been found to differ from the original description by Ehlers (1874, 1875) and is also an incorrect description of the materials themselves. Major differences between Hartman’s (1965) account and the present examination of the same specimens include the distribution of branchiae (setigers 1–9 vs. 2–5), the shape of the prostomium (narrow and pointed vs. conical and rounded), the presence or absence of thick palps, and the origin of the setae from middle of segments vs. from the anterior margin. With the morphological differences reported here, the placement of the species among the known species of Heterospio changes. Rather than H. longissima, the species most similar to H. hartmanae n. sp. are H. peruana Borowski, 1994, an abyssal species from off western South America, and H. brunei n. sp. from deep-water in the South China Sea (see below). All three species have branchiae limited to setigers 2–5, a 9-setiger thoracic region of which the first eight are short and a transitional ninth that is about 2.5 times longer than each of the first eight setigers; all nine thoracic setigers have capillary setae. The first setal cinctures occur on setiger 10, which is the first abdominal setiger. While the shape of the thick curved spines on the posterior bulbous section appears to be the same in all three species, the acicular spines in the abdominal setigers are different. In H. hartmanae n. sp. the abdominal spines in the cinctured segments are mainly simple spines with narrow rounded tips; only a few have pointed tips and none are aristate. In contrast, the acicular spines of cinctured segments in H. peruana are illustrated by Borowski (1993) as distinctly aristate or subuluncinate-like capillaries where the extended tip is thicker than the smoothly tapering tip of typical capillaries. Heterospio brunei n. sp. has a few aristate spines in the first one or two abdominal setigers, but most are acicular throughout. More importantly, H. hartmanae n. sp. has two prominent peristomial rings, whereas H. brunei n. sp. has only one. Biology. Sediment grain size data are available for the two abyssal stations off the Carolinas where Heterospio hartmanae n. sp. was collected (Blake et al. 1987; Blake & Grassle 1994). Station 13 off Cape Fear, NC, and Station 16 off Charleston, SC, were adjacent sites along the 3000 m isobath and had similar sediment characteristics; both sites had high silt + clay fractions and a water content of about 56.3%. The nine sediment samples collected at each of station, averaged over all three surveys, included the following results for percent sand, silt and clay fractions: Sta. 13: sand (17.6 ± 5.1); silt (38.8 ± 4.1); clay (43.5 ± 3.7); Sta. 16: sand (6.0 ± 1.1); silt (38.3 ± 1.1); clay (52.4 ± 1.6). Blake & Grassle (1994) reported that the polychaetes Microrbinia linea Hartman, 1965, Prionospio sp. 2, and Myriochele sp. 1 were the three most abundant species at Sta. 13 and M. linea, Prionospio sp. 2, and Siboglinum sp. 2 were the three most abundant species at Sta. 16. Heterospio hartmanae n. sp. ranked 14 th at Sta. 16. Etymology. This species is named after the late Dr. Olga Hartman, who recognized the unusual nature of Heterospio. Dr. Hartman’s lifetime of work on polychaete systematics has been an inspiration to the present authors and polychaete researchers worldwide. Distribution. Lower continental slope and abyssal depths of the Western North Atlantic Ocean, off eastern North America, 2470–4950 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 10-14, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Hartman, O. (1965) Deep-water benthic polychaetous annelids off New England to Bermuda and other North Atlantic areas. Allan Hancock Foundation Occasional Paper, 28, 1 - 378, 52 pls. [http: // digitallibrary. usc. edu / digital / collection / p 15799 coll 82 / id / 20299]","Hartman, O. & Fauchald, K. (1971) Deep-water benthic polychaetous annelids off New England to Bermuda and other North Atlantic areas Part II. Allan Hancock Monographs in Marine Biology, 6, 1 - 327, 34 pls. https: // repository. si. edu / handle / 10088 / 3458","Ehlers, E. (1874) Annulata nova vel minus cognita in Expeditione \" Porcupine \" capta. The Annals and Magazine of Natural history, Series 4, 13, 292 - 298. [https: // www. biodiversitylibrary. org / page / 24342680]","Ehlers, E. (1875) Beitrage zur Kenntniss der Verticalverbreitung der Borstenwurmer im Meere. Zeitschrift fur wissenschaftliche Zoologie, 25, 1 - 102, 4 pls. [https: // www. biodiversitylibrary. org / page / 45143254]","Blake, J. A. & Grassle, J. F. (1994) Benthic community structure on the U. S. South Atlantic slope off the Carolinas: Spatial heterogeneity in a current-dominated system. Deep-Sea Research II, 41 (4 - 6), 835 - 874. https: // doi. org / 10.1016 / 0967 - 0645 (94) 90051 - 5","Hilbig, B. (1994) Faunistic and zoogeographical characterization of the benthic infauna on the Carolina Continental slope. Deep-sea Research II, 41 (4 - 6), 929 - 950. https: // doi. org / 10.1016 / 0967 - 0645 (94) 90055 - 8","Laubier, L., Picard, C. & Ramos, J. (1974) Les Heterospionidae (Annelides Polychetes Sedentaires) de Mediterranee occidentale. Vie et Milieu, Series A, 23 (2), 243 - 254. [actual date of publication: Mar 1974] [https: // hal. sorbonne-universite. fr / hal- 02982257 / document]","Borowski, C. (1994) New records of Longosomatidae (Heterospionidae) (Annelida, Polychaeta) from the abyssal Southeast Pacific, with the description of Heterospio peruana sp. n. and general remarks on the family. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 92 (Supplement 1), 129 - 144.","Parapar, J., Aguirrezabalaga, F. & Moreira, J. (2014) First record of Longosomatidae (Annelida: Polychaeta) from Iceland with a worldwide review of the family. Journal of Natural History, 48, (17 - 18), 983 - 998. https: // doi. org / 10.1080 / 00222933.859316","Parapar, J., Vijapure, T., Moreira, J. Sukumaran, S. (2016) A new species of Heterospio (Annelida, Longosomatidae) from the Indian Ocean. European Journal of Taxonomy, 220, 1 - 17. https: // doi. org / 10.5852 / ejt. 2016.220","Blake, J. A., Hecker, B., Grassle, J. F., Brown, B., Wade, M., Boehm, P., Baptiste, E., Hilbig, B., Maciolek, N., Petrecca, R., Ruff, R. E., Starczak, V. & Watling, L. E. (1987) Study of Biological Processes on the U. S. South Atlantic Slope and Rise. Phase 2. OCS Study MMS 86 - 0096: Vol. 2. Final Report. National Technical Information Service (NTIS) No. PB 87 - 214342 and PB 87 - 214359. Prepared for the U. S. Department of the Interior, Minerals Management Service, Washington, D. C., ii + 414 pp., 13 Appendices. Available from: https: // espis. boem. gov / final % 20 reports / 4698. pdf (accessed 20 January 2021)"]}

Heterospio paulolanai new species Figure 13 urn:lsid:zoobank.org:act: 9D2C1C8E-4088-4EA7-B564-EAFB7B64AA2E Material examined. South Atlantic Ocean, Brazil, offshore São Paulo, Súeste IV, Sta. 6672 , coll. 14 Nov 1985, 24.735°S, 45.917°W, 69 m, mud and shell gravel, holotype (MZUSP 5588). Description. Holotype (MZUSP 5588) only specimen, incomplete with 12 setigers, long, narrow, 27 mm long, 1.0 mm wide across thoracic setigers, 0.8 mm wide across abdominal segments. Specimen with some segments (setigers 1, 9, and 11) damaged, partially dissected by a previous worker. Thoracic region with nine setigers, 1–8 short, 9 transitional, about 2.5 times as long as setiger 8 (Fig. 13A). Thoracic segments with defined dorso-lateral setal fascicles transitioning to abdominal segments with setae arising from broad cincture-like fascicles with rows of setae mostly surrounding anterior margin of each segment, but with wide dorsal and ventral gaps. Abdominal segments 10–12 very long, each longer than entire thoracic region. Color in alcohol brown. Pre-setiger region triangular in shape, about as long as first two thoracic setigers (Fig. 13A–B). Prostomium rhomboid-shaped, tapering to rounded tip (Fig. 13A); eyespots absent, nuchal organs narrow slits laterally at posterior junction of prostomium and peristomium (Fig. 13A). Peristomium with two dorsolateral rings apparent dorsally and laterally, separated by groove from which dorsal tentacles arise medially; no tentacles present, but scars evident in grooves. Peristomium incomplete dorsally, interrupted by posterior extension of prostomium merging with dorsal surface, dorsal crest lacking. Ventral surface of peristomium broad a single broad surface, anteriorly encompassing mouth, merging posteriorly with broad ventral surface of thoracic segments (Fig. 13B). Mouth a transverse slit consisting of simple opening between two large lateral lobes and simple anterior and posterior lips (Fig. 13B). Branchiae or their stubs present on setigers 2–8 (Fig. 13A), not observed on setiger 9 possibly due to damage from an earlier dissection; most branchiae when present long, thin, rounded in cross section, tapering to rounded tip; branchiae with narrow ciliated groove; internal blood vessel extends along entire length. All parapodia biramous with setae emerging from near anterior edge of each segment (Fig. 13A–B). Thoracic setigers with notches from which dense setal fascicles in dorsolateral locations arise on each segment; postsetal lamellae not observed, but short elevated ridge present on posterior margin of notch from which thoracic neurosetae arise; thoracic notosetae with numerous capillaries (25+) in dense fascicle with distinct rows not defined; neurosetae similarly arranged with capillaries even more numerous (~60+). Abdominal setigers from setiger 10 with setae arranged in long double rows nearly surrounding body, with relatively wide dorsal and ventral gaps. Setiger 10 with all capillaries arranged in two rows; setiger 11 with anterior row of aristate spines (Fig. 13C) and posterior row consisting of thickened capillaries (Fig. 13D); setiger 12 with anterior row of acicular spines (Fig. 13E) and posterior row of thick, curved, pointed subuluncini (Fig. 13F). Posterior region not present. Methyl Green staining. Methyl Green producing prominent pattern on pre-setiger and anterior thoracic segments. Stain concentrates on posterior and lateral margins of prostomium and both peristomial rings on dorsal and lateral surfaces. Stain also concentrates laterally on setigers 1–5 producing dark-green parapodia. Rest of body lacking distinct pattern. Remarks. Heterospio paulolanai n. sp. belongs to a group of Heterospio having a narrow conical prostomium, two peristomial rings, 7–8 pairs of branchiae, and setiger 9 as the first elongate segment about 2–3 times longer than setiger 8. Of these, H. paulolanai n. sp. is most similar to H. aruba n. sp., H. guiana n. sp., and H. sinica in having all capillaries on setiger 10 and following setigers with at least a few aristate spines. However, H. aruba n. sp. and H. paulolanai n. sp. also have acicular spines that are lacking in H. guiana n. sp. and H. sinica. Heterospio aruba n. sp. differs from H. paulolanai n. sp. in having prominent postsetal lamellae on thoracic neuropodia, an oral opening that is a narrow transverse slit with no obvious lobes or surrounding papillae, and a distinct ventral ridge that extends from the mouth posteriorly over the peristomium and first seven setigers. In contrast, H. paulolanai n. sp. has no obvious thoracic neuropodial lamellae, an oral opening bordered by two large lateral lobes, and no ventral ridge. Etymology. This species is named for the late Professor Paulo da Cunha Lana, prominent Brazilian authority on annelids. Prof. Lana was host of the sixth International Polychaete Conference held in Curitiba, Brazil (Aug 2–7, 1998) and later elected the ninth President of the International Polychaetology Association (2010–2013). Distribution. Off southeastern Brazil, 69 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 32-34, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920

Heterospio cf. reducta Laubier, Picard & Ramos, 1974 Heterospio reducta Laubier, Picard & Ramos, 1974: 246, figs. 1B–C, 3; Amoureux 1982: 185; Parapar et al. 2014, 990–995, figs. 9–10; Langeneck et al. 2017: 143–144. Material examined. Off Ireland, R / V Chain, Cruise 106, J. F. Grassle, Chief Scientist, Sta. 310 , 17 Aug 1972, Anchor dredge, 51.552°N, 12.357°W, 984– 978 m, 2 specimens (MCZ 100580). Description. Both specimens incomplete, each, long, threadlike; largest with 11 setigerous segments, 16 mm long, 0.1 mm wide along most of body. Body with seven crowded thoracic segments followed by setiger 8 about as long as setigers 1–7; setiger 9 as long as setigers 1–8. Anterior setigers slightly flattened dorsoventrally, thicker than rest of body. From setiger 9 all segments cylindrical in cross section; from setiger 10 each segment elongate appearing stretched; with numerous transverse muscle bands. Color in alcohol light tan. Prostomium broadly rounded anteriorly, flattened dorsoventrally; eyespots absent; nuchal organs grooves on posterolateral margin of prostomium. Peristomium with two rings, evident laterally, first ring narrow, second ring large, continuing across venter, interrupted dorsally by low crest. Dorsal tentacles and/or scars not present. Short, rounded pharynx everted on both specimens resulting in oral morphology not being apparent. Branchiae present on setigers 2–4; these short, stubby. All parapodia biramous with setal fascicles well separated on all setigers. Encircling rows of setae or cinctures of setae not observed on any available segments. Noto- and neuropodia of setigers 1–8 each with about 12–15 capillaries arising from narrow setal fascicles; noto- and neuropodia of setigers 9–11 each with about 20–25 capillaries arising from two rows with broad dorsal and ventral gaps, not forming cinctures. Setae all capillaries; no neuropodial hooks in anterior setigers; acicular spines, aristate spines, and subuluncini not observed. Posterior bulbous segments not present. Methyl Green staining. No pattern, stain not retained anywhere along the body. Remarks. These specimens from bathyal depths (984– 978 m) off SW Ireland agree with the morphology of Heterospio reducta as originally described by Laubier et al. (1974) from deep water (2335 m) off Algiers in the Mediterranean Sea and by Parapar et al. (2014) from bathyal depths (270–922 m) off Iceland. Amoureux (1982, 1987) also reported, but did not describe, specimens he identified as H. reducta from off W Ireland (500–1400 m). Langeneck et al. (2017) reported the species as a dominant polychaete from the Malta Escarpment in the Mediterranean, but did not describe their specimens. The species is characterized as having a broadly rounded, disklike prostomium, branchiae on setigers 2–4, with setiger 8 being the first elongated setiger, and all setae capillaries with no spines or segmental cinctures. However, no specimens having more than 12 setigers have ever been reported and therefore, complete absence of spines in abdominal segments cannot be fully confirmed until larger fragments or complete specimens are collected. It has not escaped our notice that the type locality for Heterospio longissima Ehlers, 1874, the type-species of the genus, is also off SW Ireland in bathyal depths (837 m) and only 116 km from the location of our specimens. Ehlers’ species was described for a specimen with 12 setigers with all capillary setae. Ehlers’ (1875) illustration also shows a broadly rounded prostomium, but branchiae are illustrated on setigers 2–8 instead of 2–4 and setiger 9 is the first elongate one instead of setiger 8 (see also Fig. 1 this study). Unfortunately, the original materials examined by Ehlers (1874, 1875) appear to have been lost (Laubier et al. 1974; Borowski 1994). However, the possibility that the specimens from off Ireland identified here as H. cf. reducta, might actually represent the type species should be investigated given that we have determined that Hartman’s (1965) version of H. longissima was misconstrued and her collections actually include two of our newly described species (H. hartmanae n. sp. and H. guiana n. sp.). We also note that Amoureux (1982) reported both H. longissima and H. reducta from off Ireland, but did not describe them. Amoureux (1987) later added H. mediterranea in a summary report of the “ Thalassia ” expeditions. A starting point might be to locate and examine his specimens. Some of his samples included two of these species. Distribution. Mediterranean Sea, 1200–2100, 2335 m; Off SW Ireland, 500–1400 m; off Iceland, 270– 922 m.

Heterospio catalinensis (Hartman, 1944) Figures 21–22 Longosoma catalinensis Hartman, 1944: 322, pl. 27, figs. 1–3; 1957: 336, pl. 43, fig. 8. Heterospio catalinensis Hartman 1969: 205–206, figs. 1–4. Vargas et al. 1985: 335; Maurer et al. 1988: 47. Not Fauchald et al. 2009: 786. Material examined. (44 specimens) Pacific Ocean, Allan Hancock Pacific Expeditions. Off California, Santa Catalina Island, off Long Point, R / V Velero III Sta. 900-38, coll. 18 Nov 1938, dredged, 33.41°N, 118.354°W, 73 m, rock, brachiopods, and sponges, det. Olga Hartman, holotype (LACM-AHF Poly 582).— Southern California Bight, off San Clemente Island, 1.8 miles from East End Light, R / V Velero IV Sta. 4045-56, coll. 05 Apr 1956, Hayward grab, 33.311°N, 118.281°W, 104 m, (2, LACM-AHF Poly 13295); off Santa Catalina Island, 4 miles from Long Point Light, R / V Velero IV Sta. 2144-52, coll. 07 Aug 1952, Orange peel grab, 33.403°N, 118.358°W, 82 m, fine black sand, (1, LACM-AHF Poly 13296); Orange County, off Newport Beach, 1 mile from end of Balboa Pier, R / V Velero IV Sta. 2745-54, coll. 15 May 1954, Campbell grab, 33.597°N, 117.901°W, 14.6 m, gray sand, (1, LACM-AHF Poly 13297); San Diego County, off Oceanside, 0.25 miles from Oceanside Pier, R / V Velero IV Sta. 4761-56 , coll. 08 Dec 1956, Hayward grab, 33.197°N, 117.392°W, 9.1 m, black silt, (6, LACM-AHF Poly 13298); San Diego County, off Del Mar, 1.95 miles from Del Mar Stack, R / V Velero IV Sta. 5772-58 , coll. 01 Aug 1958, Hayward grab, 32.987N, 117.291°W, 23.7 m, olive green silty sand (1, LACM-AHF Poly 13299); Orange County, off San Juan Capistrano, 0.75 miles from San Juan Capistrano Pier, R / V Velero IV Sta. 4774-56 , coll. 10 Dec. 1956, Hayward grab, 33.49°N, 117.663°W, 11.9 m, black & dark green very fine sand, oily & H 2 S (2, LACM-AHF Poly 13300); San Diego County, 0.7 miles from Cardiff by the Sea Tower, R / V Velero IV Sta. 4759-56, coll. 08 Dec 1956, Hayward grab, 33.031°N, 117.296°W, 36. 5 m, very fine green sand (16, LACM-AHF Poly 13302); Off Santa Catalina Island, 47 miles from Jewfish Point, R / V Velero IV Sta. 2122-52, coll. 19 Jun 1952, Orange peel grab, 33.318°N, 118.294°W, 87.8 m, (2, LACM-AHF Poly 13303); San Diego County, off Oceanside, 0.25 mile from Oceanside Pier, R / V Velero IV Sta. 4761- 56, coll. 08 Dec 1956, Hayward grab, 33.197°N, 117.392°W, 9.1 m, black silt, (3, LACM-AHF Poly 13304); S an Diego County, off Oceanside, 7.6 miles from Oceanside Pier, R / V Velero IV Sta. 4867-57 , coll. 20 Feb 1957, Hayward grab, 33.293° N, 117.482 W, 11.9 m (5, LACM-AHF Poly 13305).— Southern California Bight Survey, E Santa Barbara Channel, Santa Barbara County, Sta. Bight 03-4047, coll. ABC Laboratories, 24 Jul 2003, van Veen grab, 34.39548°N, 119.66218°W, 24.7 m, soft bottom (1, LACM-AHF Poly 13291); Los Angeles County, off Malibu, Nicholas Canyon Beach, Sta. Bight 03-4069, coll. City of Los Angeles Environmental Monitoring, 31 Jul 2003, van Veen grab, 34.036°N, 118.917°W, 15.5 m, soft bottom (1, LACM-AHF Poly13292); E Santa Barbara Channel, Ventura County, off Emma Wood State Beach, Sta. Bight 03-4043, coll. ABC Laboratories, 23 Jul 2003, van Veen grab, 34.284°N, 119.355°W, 18.2 m, soft bottom, (1, LACM-AHF Poly 13293); Ventura County, SE of San Miguel Island, Sta. Bight 03-4421, coll. Channel Islands National Marine Sanctuary, 21 Aug 2003, van Veen grab, 33.988°N, 120.38°W, 95 m, soft bottom, (1, LACM-AHF Poly 13294). Description. A moderately sized species, all specimens incomplete; however one posterior fragment available. Body elongate, anterior eight segments crowded, dorsoventrally flattened, each about three times as wide as long; setiger 9 first elongate segment (Fig. 21A), becoming more cylindrical; abdominal segments 10–13 long, narrow and cylindrical in cross section; one posterior fragment with an elongate bulbous posterior end. Holotype (LACMAHF Poly 582) an 11-setiger anterior fragment, 15 mm long, 1.2 mm wide across thoracic segments; a 12-setiger anterior fragment (LACM-AHF Poly 13294) 20.1 mm long, 0.9 mm wide across setiger 4 (Fig. 21A–B); a 13- setiger anterior fragment (LACM-AHF Poly 13298) 11 mm long, 1.2 mm wide across thorax (Fig. 22A). Color in alcohol light tan; pigment entirely absent. Pre-setiger region triangular in shape, relatively short, about as long as first two thoracic setigers (Fig. 21A). Prostomium conical, tapering to narrow rounded tip, dorsally merging posteriorly with peristomium and continuing to border of setiger 1 (Fig. 21A); eyespots absent, nuchal organs narrow slits along posterior margin. Peristomium large, ventrally entire, dorsally separated into two rings by two curved grooves from which dorsal tentacles arise (Fig. 21A); one of two dorsal tentacles attached on one specimen (Fig. 22A: LACM-AHF Poly 13298); dorsal tentacles large, thick, with prominent folds and a deep ventral groove (Fig. 22A). Ventrally, mouth from margin of prostomium, consisting of narrow vertical slit between four large lateral lobes and single ventral row of 4–5 short lobes (Fig. 22B); proboscis everted on several specimens as a short inflated lobe. Thoracic region defined by eight short crowded setigers followed by an elongate setiger 9 about four times as long as setigers 6–8 combined (Fig. 21A). Transition from thoracic segments with defined dorsolateral setal fascicles to abdominal segments denoted by setae arising from broad cincture-like rows mostly surrounding anterior margin of each segment occurs at setiger 10 (Fig. 21A). Branchiae or their stubs present on setigers 2–9 (Fig. 21A); most branchiae when present long, thin, rounded in cross section, tapering to rounded tip; weakly moniliform (Figs. 21A, 22A). All parapodia of thoracic and abdominal regions biramous with setae emerging from near anterior edge of each segment; two posteriormost setigers of posterior bulbous region with only notosetae. Thoracic notopodia reduced to low inconspicuous mounds with setae arising from notch; neuropodia with a low rounded postsetal lamella on setigers 1–8 (Fig. 21B). Thoracic setigers 1–9 with dense fascicles of capillary setae in dorsolateral locations on each segment; thoracic notosetae numerous capillaries in dense fascicles consisting of five or more curved rows; neurosetae of setiger 1 with about 6–10 curved elongate and narrow acicular spines preceded by at least two rows of capillaries (Figs. 21A–B, 22A); neurosetae of setigers 2–9 numerous capillaries. Hooks of setiger 1 unidentate, weakly sigmoid, with tip sharply curving to narrow blunted tip (Figs. 21D, 22C). Abdominal setigers from setiger 10 with parapodia as low ridges bearing setae arranged in long double rows almost entirely surrounding body; with small dorsal, ventral, and lateral gaps approximating separate noto- and neuropodia; setigers 10–12 with numerous capillaries in both rows. Setiger 13 with anterior row of subuluncinate spines tapering to tapering tip, some appearing aristate (Figs. 21E, 22D); posterior row of setae with numerous capillaries. Posterior fragment with three parapodia anterior to bulbous posterior section; these parapodia possibly representing setigers 18–20 have only two rows of capillaries without any spinous setae. Posterior region an elongate bulbous section, about 3.5 times longer than wide, distinctly set off from elongate abdominal segments (Figs. 21C, 22B); with six setigers, each with a pair of curved hooks with pointed tips (Figs. 21F–I, 22D–F); first four of these posterior setigers with noto- and neuropodial spines, last two with only notopodial spines. Methyl Green staining. Stain concentrated dorsolaterally on peristomial rings, and laterally anterior and posterior to each set of noto- neuropodial setal fascicles from setiger 1 to at least setiger 12; branchiae and neuropodial lamellae not retaining stain. Remarks. Heterospio catalinensis (as Longosoma) was the second species of the genus to be described after Ehlers (1874, 1875) described H. longissima and the first reported to have acicular spines in the neuropodia of setiger 1 (Hartman 1944). To date, including the present study, four species of Heterospio have been reported with neuropodial spines on setiger 1: H. catalinensis (Hartman 1944, 1957; Southern California), H. sp. A (Uebelacker 1984; Gulf of Mexico), H. alata n. sp. (South China Sea), and H. bidentata n. sp. (Coral Sea off E. Australia). Of these H. catalinensis and H. sp. A from shallow shelf depths have unidentate spines in setiger 1, whereas H. alata n. sp. and H. bidentata n. sp. have bidentate spines on setiger 1 and are both deep-water species. Despite H. catalinensis having been described relatively early in Heterospio history by Hartman (1944), and from southern California where numerous surveys have taken place, there have been few subsequent reports of the species, apart from Hartman herself in 1957 and 1969. The reports of the species from Costa Rica by Vargas et al. (1985) and Maurer et al. (1988) did not provide any additional morphological observations. The present account, therefore, is the first to include updated morphological observations for the species in the 65 years since Hartman (1957). Fauchald et al. (2009) referred Uebelacker’s 1984 report of Heterospio sp. A from the Gulf of Mexico to H. catalinensis; however, we disagree with this assignment. Heterospio catalinensis and H. sp. A are similar, but differ in the following respects: H. catalinensis has branchiae on setigers 2–9, low, rounded neuropodial postsetal lamellae occur on setigers 1–8, setiger 9 is the first elongate setiger, about four times as long as setiger 8, and the modified neuropodial hooks on setiger 1 are long and have a sharply curved tip; H. sp. A in contrast, has branchiae on setigers 2–6 (or 7), neuropodial postsetal lamellae are not reported, setiger 8 is the first elongate setiger and about twice as long as setiger 7, and the modified neuropodial spines of setiger 1 are hirsute with a bluntly rounded apex rather than sharply curved. Based on the present study of H. catalinensis and Uebelacker’s (1984) description of H. sp. A, both species have only capillaries on abdominal setigers 10–12 with spines first present from setiger 13. Hartman (1957) was the first to report subuluncini in H. catalinensis but did not indicate on which abdominal setigers they occurred. Here we report the presence of subuluncini on setiger 13 in H. catalinensis, while Uebelacker (1984) reported both acicular and subuluncinate spines, also from setiger 13, on H. sp. A. Given the morphological differences and disjunct geographic locations between H. catalinensis and H. sp. A, the Gulf of Mexico specimens most likely represent a separate undescribed species rather than H. catalinensis as listed by Fauchald et al. (2009). Records of H. catalinensis from the Gulf of California in 1550–1590 m by Mendez (2006, 2007) are likely not this species because of their much greater collection depth. Biology. Heterospio catalinensis is widely distributed offshore southern California and although the original collection reports it being dredged from bottoms with rock, brachiopods, and sponges (Hartman 1944) other more recent records from grab samples are from soft bottoms consisting of fine sands. Distribution. Southern California, 9–104 m; Costa Rica, Gulf of Nicoya, 20– 46 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 44-48, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Hartman, O. (1944) Polychaetous annelids. Part VI. Paraonidae, Magelonidae, Longosomidae, Ctenodrilidae, and Sabellariidae. Allan Hancock Pacific Expeditions, 10 (3), 311 - 481, pls. 27 - 42. [https: // www. biodiversitylibrary. org / page / 4680266]","Hartman, O. (1969) Atlas of the Sedentariate Polychaetous Annelids from California. Allan Hancock Foundation, University of Southern California, Los Angeles, California, 812 pp.","Vargas, J. A. Dean, H. K., Maurer, D. & Orellana, P. (1985) Lista preliminary de invertebrados asociados a los sedimentos del Golfo de Nicoya, Costa Rica. Brenesia, 24, 327 - 342.","Maurer, D., Vargas, J. A. & Dean, H. K. (1988) Polychaetous annelids from the Gulf of Nicoya, Costa Rica. Internationale Revue der gesamten Hydrobiologie und Hydrographie, 73, 43 - 59. https: // doi. org / 10.1002 / iroh. 19880730105","Fauchald, K. Granados-Barba, A. & Solis-Weiss, V. (2009) Polychaeta (Annelida) of the Gulf of Mexico. In: Felder, D. L. & Camp, D. K. (Eds.), Gulf of Mexico. Origin, Waters, and Biota. Vol. 1. Biodiversity. Texas A & M University Press, College Station, Texas, pp. 751 - 788. [https: // books. google. es / books? id = CphA 8 hiwaFIC & lpg = PR 1 & pg = PA 751]","Ehlers, E. (1874) Annulata nova vel minus cognita in Expeditione \" Porcupine \" capta. The Annals and Magazine of Natural history, Series 4, 13, 292 - 298. [https: // www. biodiversitylibrary. org / page / 24342680]","Ehlers, E. (1875) Beitrage zur Kenntniss der Verticalverbreitung der Borstenwurmer im Meere. Zeitschrift fur wissenschaftliche Zoologie, 25, 1 - 102, 4 pls. [https: // www. biodiversitylibrary. org / page / 45143254]","Hartman, O. (1957) Orbiniidae, Apistobranchidae, Paraonidae and Longosomidae. Allan Hancock Pacific Expeditions, 15 (3), 211 - 393, pls. 20 - 44, 1 chart. [https: // biodiversitylibrary. org / page / 4160176]","Uebelacker, J. M. (1984) Chpater 10. Family Heterospionidae Hartman, 1963. In: Uebelacker, J. M., Johnson, P. G., Vittor, B. A. & Associates (Eds.), Taxonomic Guide to the Polychaetes of the Northern Gulf of Mexico. Vol. II. U. S. Department of the Interior, Minerals Management Service, Metairie, Louisiana, pp. 10 - 1 - 10 - 6. Available from: https: // espis. boem. gov / final % 20 reports / 3865. pdf (accessed 9 September 2022)","Mendez, N. (2006) Deep-water polychaetes (Annelida) from the southeastern Gulf of California, Mexico. Revista de Biologia Tropical, 54, 773 - 785. https: // doi. org / 10.15517 / rbt. v 54 i 3.12776","Mendez, N. (2007) Relationships between deep-water polychaete fauna and environmental factors in the southeastern Gulf of California, Mexico. Scientia Marina, 71 (3), 605 - 622. https: // doi. org / 10.3989 / scimar. 2007.71 n 3605"]}

Heterospio dibranchiata new species Figures 8–9 urn:lsid:zoobank.org:act: 1FB493ED-53AC-4828-BE77-784002C767DD Material examined. (40 specimens) Gulf of Mexico, off Louisiana. Matterhorn Platform Survey, coll. J. A. Blake, Chief Scientist. Sta. M-5S, 10 Nov 2008, BC, 28.724°N, 88.826°W, 955 m, holotype (MCZ 163727), 9 paratypes (MCZ 163728); Sta. M-1S, 10 Nov 2008, BC, 28.739°N, 88.826°W, 875 m (2, MCZ 163729); Sta. M-2S, 10 Nov 2008, BC, 28.738.738°N, 88.826°W, 878 m, 1 paratype (MCZ 163730); Sta. M-3S, 10 Nov 2008, BC, 28.737°N, 88.826°W, 884 m, 2 paratypes (MCZ 163731); Sta. M-4S, 10 Nov 2008, BC, 28.733°N, 88.826°W, 908 m, 1 paratype (MCZ 167732); Sta. M-1E, 10 Nov 2008, BC, 28.742°N, 88.822°W, 867 m, 1 paratype (MCZ 163733); Sta. M-2E, 10 Nov 2008, BC, 28.742°N, 88.821°W, 867 m, 1 paratype (MCZ 163734); Sta. M-3E, 10 Nov 2008, BC, 28.742°N, 88.82°W, 868 m, 2 paratypes (MCZ 163735); Sta. M-4E, 10 Nov 2008, BC, 28.742°N, 88.815W 891 m (1, MCZ 163736); Sta. M-5E, 09 Nov 2008, BC, 28.742°N, 88.805°W, 921 m, 3 paratypes (MCZ 163737); Sta. M-2N, 10 Nov 2008, BC, 28.746°N, 88.826°W, 825 m (1, MCZ 163738); Sta. M-4N, 10 Nov 2008, BC, 28.752°N, 88.826°W, 821 m, 1 paratype (MCZ 163739); Sta. M-3W, 10 Nov 2008, BC, 28.742N, 88.831°W, 850 m, 2 paratypes (MCZ 163740); Sta. M-4W, 10 Nov 2008, BC, 28.742°N, 88.837° W, 839 m, 1 paratype (MCZ 163741).— Virgo Platform Survey, coll. J.A. Blake, Chief Scientist. Sta. V-1E, 11 Nov 2008, BC, 29.182°N, 88.164°W, 340 m (1, MCZ 163742); Sta. V-1W, 11 Nov 2008, BC, 29.185°N, 88.172°W, 340 m (1 post end MCZ 167743); Sta. V-1N, 11 Nov 2008, BC, 29.185°N, 88.171°W, 335 m (1, MCZ 163744).— Matterhorn Gas Pipeline Survey, coll. P.A. Neubert, Chief Scientist. Sta. 2C, 05 Jun 2009, BC, 28.872°N, 88.88°W, 533 m (3, MCZ 163745); Sta. 6C, 04 Jun 2009, BC, 28.872°N, 88.941°W, 282 m (1, MCZ 163746); Sta. 8C, 04 Jun 2009, BC, 28.863°N, 88.984°W, 241 m (1, MCZ 163747); Sta. 9C, 04 Jun 2009, BC, 28.897°N, 88.946°W, 229 m (2, MCZ 163748).— Matterhorn Oil Export Pipeline Survey, coll. J.A. Blake, Chief Scientist, Sta. 4, 10 Jul 2008, 28.821°N, 88.985W, 364 m (1, MCZ 154127). Description. An elongate, threadlike species. Holotype (MCZ 163727) complete, with 27 setigers (9 thoracic, 15 abdominal, 3 on posterior section), 14.9 mm long, 0.1 mm wide across narrow thoracic setigers, 0.26 mm wide across middle abdominal segments, and 0.22 wide across bulbous posterior section (Fig. 8A). A smaller complete specimen (MCZ 163744) with 28 setigers (9 thoracic, 15 abdominal, 4 on posterior section), 7.27 mm long, 0.08 mm wide across thoracic setigers, 0.12 mm wide across abdominal segments, and 0.07 mm across posterior section. One small complete juvenile also present (see below). Paratypes and other specimens incomplete. Large paratype (MCZ 163735) with 13 setigers, 23.3 mm long, 0.21 mm wide across thoracic setigers, and 0.71 mm across abdominal segments; small paratype (MCZ 163728) with 13 setigers, 5.71 mm long, 0.15 across thoracic setigers, 0.12 across abdominal segments. Body divided into thoracic region with nine setigers, setigers 1–6 short, slightly wider than long; setigers 7–9 becoming progressively longer with setiger 7 about 2 times longer than setiger 6, setiger 8 about 3.5 times longer than setiger 6; setiger 9 greatly elongated, about 9 times longer than setiger 6. Color in alcohol opaque white to light tan; pigment entirely absent. Pre-setiger region short, as long as first two thoracic setigers (Fig. 9A–C). Prostomium narrow, triangular, tapering to narrow apex (Fig. 9A–C); eyespots absent; nuchal organs distinct slits on posterior lateral margins (Fig. 9A–B). Dorsal surface with narrow ridge or crest extending from prostomium mid-dorsally over peristomium (Fig. 9B). Peristomium a single ring, interrupted dorsally by dorsal ridge (Fig. 9A–B). Mouth narrow vertical opening bordered anteriorly by three short narrow lobes, laterally by two large protruding lobulated lobes that could be mistaken for protruding proboscis, and posteriorly by 7–9 lobes connecting to elongate narrow ridge extending posteriorly over peristomium and setigers 1–2 (Fig. 9C). Dorsal tentacles observed on one specimen, arising in groove or notch lateral to dorsal crest; tentacles thickened filaments. Branchiae present on setigers 2–3 (Figs. 8A–B, 9A–B) on all specimens examined except smallest juveniles, where present only on setiger 2; branchiae long, thin (Fig. 8B), rounded in cross section, tapering to rounded tip; each with narrow ciliated groove; internal blood vessel extends along entire length. All parapodia biramous with setal fascicles arising from near anterior edge of segment. All thoracic setigers slightly flattened dorsally with parapodia weakly inflated and elevated over dorsum and bearing setal fascicles in tight bundles. Abdominal setigers 10 and following round in cross section and bearing setae in transverse rows encircling each anterior end of segment. Abdominal parapodia from setiger 10 narrow elongate lobes, becoming thicker and more prominent from setigers 11–12; noto- and neuropodia with distinct dorsal and ventral gaps between setal fascicles; lateral gaps between noto- and neuropodia narrower. Thoracic notopodia of setigers 1–9 with 10–15 long capillaries in spreading fascicles; capillaries of neuropodia more numerous, with up to 20–25 setae arranged in tight, dense fascicle. Noto- and neuropodia of setiger 10 with capillaries arranged in two elongate transverse rows with distinct dorsal and lateral gaps. Setiger 11 with notosetae of both rows all capillaries; neuropodia with anterior row of acicular spines and posterior row with capillaries; setiger 12 with both noto- and neuropodia with anterior row of acicular spines and posterior row of capillaries. Setiger 13 and all subsequent abdominal setigers (to setiger 24 in holotype) with both noto- and neuropodia with anterior row of acicular spines and posterior row of narrower spines with long aristate tip. Acicular spines thick, tapering to narrow pointed tip (Figs. 8D–E, 9D); aristate spines narrower than acicular spines, with long, tapering tip (Figs. 8D–E, 9E–G). Far posterior bulbous section of holotype oval-shaped (Fig. 8C), with terminal anal opening; with three parapodia, each bearing 1–2 hooked spines in each ramus; each spine short, with curved pointed tip (Fig. 8F). Juvenile morphology. A complete juvenile with 28 setigers (MCZ 163745) with nine thoracic, 16 abdominal, and three posterior setigers; 4.94 mm long and 0.06 mm across anterior setigers; body consistently narrow except for bulbous posterior end. A pair of long branchiae present on setiger 2 but absent on setiger 3. Setigers 7, 8, and 9 longer than individual setigers 1–6, but setiger 9 not as long proportionately as in adults; all abdominal segments of a relatively equal length.A second complete juvenile from Sta. 6C (MCZ 163746) with 28 setigers: nine thoracic, 15 abdominal, and four posterior, measuring 3.3 mm long, 0.73 mm across thoracic setigers, 1.22 mm across abdominal setigers, and 0.91 across the posterior section. This second juvenile with abdominal segments contracted, thus appearing shorter. Posterior bulbous section of juveniles similar in appearance to that of adults. Transverse setal fascicles of abdominal segments greatly reduced in juveniles, restricted to simple noto- and neuropodia with fewer setae (4–6 spines per fascicle), but have same arrangement of acicular spines and aristate spines in two rows as in adults from setiger 13. Short curved hooks in posterior region of same morphology, arrangement, and number as in adults. These observations suggest that full segmental complement of 27–28 or more setigers of Heterospio dibranchiata n. sp. develop early in juveniles and that subsequent growth involves elongation, enlargement, and elaboration of individual segments and parapodia as well as an increase in number of setae. It is likely that this same growth pattern occurs in all species of Heterospio. Methyl Green staining. Body stains uniformly; weak staining of pre-setigerous region not prominent. Remarks. Heterospio dibranchiata n.sp. is unusual within the genus in having only two pairs of branchiae(setigers 2–3); these branchiae are remarkably long, and when complete are as long as one-third or more of the body length. Other unusual characters include: (1) a conical prostomium with a narrow anterior apex and a posterior extension or caruncle that extends over the peristomium as a dorsal crest merging with setiger 1, (2) a single peristomial ring instead of two where the curved nuchal organs can be seen immediately anterior to the peristomium on the posterior lateral margin of the prostomium, (3) a notch on the anterior border of the peristomium where the dorsal tentacles are attached, (4) an unusual oral apparatus where a narrow vertical oral opening is bordered laterally by two large protruding lobes resembling a protruding pharynx, and (5) only six short thoracic segments with setigers 7, 8, and 9 becoming increasingly longer, and setiger 9 is as long as setiger 10 of other species. Other characters are more typical of known species, such as the first nine setigers (thorax) having widely spaced and well-defined noto- and neuropodia with setal fascicles in setiger 10 that transition to setae arranged in transverse rows across each noto- and neuropodia, nearly encircling the body; when spines are present, these encircling rows of setae resemble the cinctures of spines found in cirratulids of the genus Chaetozone. The hooked spines of the posterior bulbous section are similar to those reported for H. hartmanae n. sp. and others in this study. Another species in this study found to have only two pairs of branchiae and a single peristomial ring is H. alata n. sp. from off Brunei, Island of Borneo (see below). However H. alata n. sp. is one of only four known species to have neuropodial hooks on setiger 1, whereas H. dibranchiata n. sp. has only capillaries in that position. Biology. The presence of four complete specimens in these samples is unusual for a species of Heterospio and likely represents the careful manner in which they were collected; gentle handling minimized fragmentation and damage (see Materials and methods). Heterospio dibranchiata n. sp. was widely distributed in the various survey samples at the platform and pipeline locations ranging from 241 – 955 m. About a third of the specimens (10) were collected from a single sample at Station M-5S at a depth of 955 m, the deepest location from which the species was collected. Sediment grain size at Sta. M-5S was sand (1.86%), silt (34.00%), and clay (64.14%), with TOC at 1.24%. Station M-5S (955 m) was the only location where H. dibranchiata n. sp. was among the top 10 species. The station was dominated by aplacophoran molluscs, polychaetes including cirratulids, paraonids, and spionids, and a thyasirid bivalve mollusc (Blake et al. unpublished data). Etymology. The epithet dibranchiata is from the Greek, di -, for two or double and branchos for gill in reference to this species having only two pair of branchiae. Distribution. U.S. northern Gulf of Mexico, off Louisiana, 241– 955 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 23-27, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920

Heterospio indica Parapar, Vijapure, Moreira & Sukumaran, 2016 Figure 29 Heterospio indica Parapar, Vijapure, Moreira & Sukumaran, 2016: 4–14, figs. 1–8. Heterospio longissima: Rosenfeldt 1989: 231, fig. 7. Not Ehlers, 1874, 1875. Fide Parapar et al. (2016). Heterospio longissima: Hartman 1974a: 232; 1974b: 625; Wehe & Fiege 2002: 60; Not Ehlers, 1874, 1875. Material examined. (2 specimens ) Indian Ocean, International Indian Ocean Expedition, R / V Anton Bruun, Cruise 4B, Arabian Sea, Off Pakistan, S of Karachi, off mouth of Indus River, Sta. 230B, coll. 15 Nov 1963, John Ryther, Menzies Trawl, 23.517ºN, 66.917ºE, 88 m, sand, green clay, mud, (1, LACM-AHF Poly 13286).— R / V Anton Bruun, Cruise 4B, Arabian Sea off Madhavpur, India, Sta. 210A, coll. 16 Nov. 1963, John Ryther, Gulf of Mexico shrimp trawl, 21.117°N, 69.8°E to 21.15°N, 69.8°E, 34–37 m, (1, LACM-AHF Poly 13287). Description. Both specimens incomplete, each with 12 setigers. Body long, narrow, with evidence of tearing at posterior end; without longitudinal grooves or ridges along dorsal and ventral surfaces. Segmental boundaries denoted entirely by location of parapodia and setal fascicles. Body with nine anterior thoracic setigers with first eight crowded, each about five times wider than long (Fig. 29A–B), followed by an elongated setiger 9 about three times longer than each of first eight setigers. Following three abdominal segments each about as long as entire thoracic region. Largest specimen (LACM-AHF Poly 13286) 25 mm long and 1.1 mm wide across setiger 6; second specimen (LACM-AHF Poly 13287) smaller, 8.3 mm long and 0.5 mm wide. Color in alcohol opaque white; pigment entirely absent. Pre-setiger region triangular in shape, about as long as first three thoracic setigers (Fig. 29A–B). Prostomium conical, wide basally, tapering to broadly rounded tip (Fig. 29A–B); eyespots absent, nuchal organs narrow slits along posterior-lateral margin. Peristomium with two rings, separated by groove extending across ventral surface (Fig. 29B), interrupted dorsally by dorsal crest extending from prostomium to setiger 1 (Fig. 29A); no dorsal tentacles present, but scars evident in medial notch in dorsal groove between peristomial rings. Mouth arising on first peristomial ring, located between two large lateral lobes and a single posterior lobe or lip (Fig. 29B); proboscis not emergent on either specimen. Branchiae present on setigers 2–9 on both specimens (Fig. 29A); most reduced to scars or stubs, but when present, branchiae long, thin, rounded in cross section, tapering to rounded tip; branchiae with narrow ciliated groove; internal blood vessel extending along entire length. All parapodia biramous with setal fascicles arising from near anterior edge of each segment.All thoracic setigers slightly flattened dorsally with parapodia weakly inflated dorsally and bearing setal fascicles in tight bundles. Neuropodia with prominent digitate postsetal lobe on all nine thoracic setigers (Fig. 29B). Abdominal setigers round in cross section and bearing setae in two transverse rows encircling anterior border of each segment. Abdominal parapodia from setiger 10 as narrow transverse and elongate lobes, encircling anterior margin of setigers 10–12; noto- and neuropodia with distinct dorsal and ventral gaps between setal fascicles; lateral gaps between noto- and neuropodia narrower. All thoracic notopodia of setigers 1–9 with 50–75 long capillaries in dense spreading fascicles; neuropodia with similar numbers of capillaries in dense fascicles. Noto- and neuropodia of setiger 10 with thin capillaries arranged in two transverse rows with distinct dorsal and lateral gaps (Fig. 29A–B). Setigers 11–12 with anterior row containing thick spinous setae and posterior row with thin capillaries; spinous setae all with thick shaft, tapering to long, aristalike tip (Fig. 29C–F); these resembling different forms of subuluncini and aristate spines rather than capillaries as stated in Parapar et al. (2016). The few simple acicular spines present may be ones where tip has broken off. Posterior region not present among fragments. Methyl Green staining. Body staining uniformly; most of prostomium not staining, otherwise no pattern. Remarks. The present specimens from shallow water in the Arabian Sea were originally referred to H. longissima by Hartman (1974a –b) and are here redescribed and referred to the recently described H. indica by Parapar et al. (2016) from the west coast of India.Although not mentioned by Parapar et al. (2016), a distinct dorsal peristomial crest and prominent neuropodial postsetal lamellae on thoracic setigers 1–9 were illustrated by these authors and occur in the present specimens. The only other species to have such prominent postsetal lamellae is H. aruba n. sp. described from shallow water in the Caribbean Sea (see above). The two species differ in that H. indica has both peristomial rings prominent on the ventral surface and the small oval mouth opening is surrounded by two large lateral lobes and a single posterior lobe; in contrast, H. aruba n. sp. has a smooth ventral surface lacking peristomial rings and the mouth is a simple transverse slit not surrounded by prominent oral lobes. In addition, H. aruba n. sp. lacks a dorsal peristomial crest instead of having one. Heterospio aruba n. sp. has branchiae on setigers 1–8 instead of 1–9; however, these specimens are smaller than recorded for H. indica and it is possible an additional branchia might develop with further growth. Although few specimens are available, it appears as if the neuropodial postsetal lamellae of H. aruba n. sp. are short over the first 1–3 setigers and then become longer over setigers 4–8 and then short again on setiger 9. In contrast, the neuropodial postsetal lamellae of H. indica are of a similar length over all nine setigers. Parapar et al. (2016) described the spinous setae as different types of capillaries; however our interpretation is that these setae resemble the different kinds of subuluncini and aristate spines reported from species of Heterospio here and elsewhere. Distribution. Arabian Sea, off Pakistan and W India 34–88 m (this study); W India 2.5–22 m (Parapar et al. 2016)., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 58-60, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Parapar, J., Vijapure, T., Moreira, J. Sukumaran, S. (2016) A new species of Heterospio (Annelida, Longosomatidae) from the Indian Ocean. European Journal of Taxonomy, 220, 1 - 17. https: // doi. org / 10.5852 / ejt. 2016.220","Rosenfeldt, P. (1989) Die Polychaeta der Rotmeer-Expeditionen MESEDA I (1977) mit FS \" SONNE \" und MESEDA II (1979) mit FS \" VALDIVIA \". Senckenbergiana Biologica, 69, 213 - 242.","Ehlers, E. (1874) Annulata nova vel minus cognita in Expeditione \" Porcupine \" capta. The Annals and Magazine of Natural history, Series 4, 13, 292 - 298. [https: // www. biodiversitylibrary. org / page / 24342680]","Ehlers, E. (1875) Beitrage zur Kenntniss der Verticalverbreitung der Borstenwurmer im Meere. Zeitschrift fur wissenschaftliche Zoologie, 25, 1 - 102, 4 pls. [https: // www. biodiversitylibrary. org / page / 45143254]","Hartman, O. (1974 a) Polychaetous annelids of the Indian Ocean including an account of species collected by members of the international Indian Ocean Expeditions, 1963 - 64 and a catalogue and bibliography of the species from India. Journal of the Marine Biological Association of India, 16, 191 - 252. [http: // demo. initechnologies. com / mbai / php / journaldload. php? id = 817 & bkid = 48]","Hartman, O. (1974 b) Polychaetous annelids of the Indian Ocean including an account of species collected by members of the international Indian Ocean Expeditions, 1963 - 64 and a catalogue and bibliography of the species from India. Part II. Journal of the Marine Biological Association of India, 16, 609 - 644. [http: // demo. initechnologies. com / mbai / php / journaldload. php? id = 855 & bkid = 49]","Wehe, T. & Fiege, D. (2002) Annotated checklist of the polychaete species of the seas surrounding the Arabian Peninsula: Red Sea, Gulf of Aden, Arabian Sea, Gulf of Oman, Arabian Gulf. Fauna Arabia, 19, 7 - 238. Available from: https: // www. senckenberg. de / wp-content / uploads / 2019 / 10 / wehe __ fiege. pdf (accessed 11 November 2022)"]}

Heterospio peruana Borowski, 1994 Heterospio peruana Borowski, 1994: 131–136, figs. 1, 2A–G. Material examined. Pacific Ocean, SEPBOP, off Western South America, Peru-Chile Trench, R / V Anton Bruun, Cruise 11, Sta. 95, coll. 15 Oct 1965, R. J. Menzies, 08.517°S, 81.667°W, Menzies trawl, 4332–4423 m, 1 specimen in two parts (LACM-AHF Poly 13306). Description. A single incomplete specimen in two parts, not in good condition; anterior fragment with 12 setigers, 12.5 mm long and a posterior fragment with two segmental setigers and intact bulbous posterior end with five setigers with hooks. Pre-setiger region with conical, broadly rounded prostomium and two peristomial rings, incomplete dorsally; without dorsal crest; nuchal organs in groove between prostomium and first peristomial ring; dorsal tentacles not present. Thoracic segments flattened dorsally, rounded ventrally. Thoracic setigers 1–8 short, about twice as wide as long; setiger 9 first elongate segment, about twice as long as setiger 8. Setiger 10 first abdominal segment, as long as entire thoracic region; setigers 11 and 12 equally as long as setiger 10. Branchiae on setigers 2–5 reduced to scars or stubs on this specimen. All setigers biramous. Thoracic parapodia as rounded pads without postsetal lamellae; with noto- and neuropodia well separated, bearing 20–30 thin capillaries in tight well-defined fascicles. Parapodia of abdominal setigers 10–12 as transverse low ridges, with setae in two rows mostly surrounding body; first row with numerous thickened spinous setae and second row with thin capillaries. Spinous setae of setiger 10 mostly aristate or subuluncinilike with an elongated tapering point. Spines of setiger 12 with those of notopodia mostly aristate, and those of neuropodia mostly acicular. Bulbous posterior end with five setigers bearing large curved hooks in each ramous. Methyl Green staining. Not tested due to poor condition of specimen. Remarks. These fragments from the Peru-Chile Trench agree well with the original account by Borowski (1994) from the abyssal plain of the Peru Basin, except that the abdominal neurosetae tend to be more acicular rather than aristate or subuluncini as in the notopodia. By having branchiae on setigers 2–5 and setiger 9 as the first elongate segment, ca. 2–2.5 times as long as the shorter thoracic setigers, Heterospio peruana most closely resembles H. hartmanae n. sp. from the North Atlantic Ocean and H. brunei n. sp. from the South China Sea. All three of these widely separated species are from abyssal or lower continental slope depths. In H. hartmanae n. sp. the abdominal spines in the cinctured abdominal segments are mainly simple spines with narrow rounded tips; only a few have pointed tips and none are aristate. In contrast, the acicular spines of cinctured segments in H. peruana are illustrated by Borowski (1994) as distinctly aristate or subuluncinate-like capillaries where the extended tip is thicker than the smoothly tapering tip of typical capillaries. In the present study aristate spines have been observed, but also acicular spines in some abdominal neuropodia. Heterospio brunei n. sp. has a few aristate spines in the first one or two abdominal setigers, but most are acicular throughout. H. hartmanae n. sp. and H. peruana have two prominent peristomial rings, whereas H. brunei n. sp. has only one. Distribution. Abyssal Plain, DISCOL manganese nodule site, Peru Basin, 4125–4188 m (Borowski 1994); Peru-Chile Trench, 4423 m (This study)., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on page 53, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Borowski, C. (1994) New records of Longosomatidae (Heterospionidae) (Annelida, Polychaeta) from the abyssal Southeast Pacific, with the description of Heterospio peruana sp. n. and general remarks on the family. Mitteilungen aus dem Hamburgischen Zoologischen Museum und Institut, 92 (Supplement 1), 129 - 144."]}

Nineteen species of the rare polychaete genus Heterospio are reported, 15 of which are new to science. The status of H. longissima Ehlers, 1874, the type-species, is reviewed. The specimens examined are from several locations in the North Atlantic Ocean, Gulf of Mexico, Caribbean Sea, off Br azil, the Indian Ocean, the Pacific Ocean off California, New Zealand, Australia, and the South China Sea. Deep-water samples from the western North Atlantic Ocean collected by the late Drs. H.L. Sanders and R.R. Hessler that were reported by Hartman as H. longissima were re-examined and referred to two new species, H. hartmanae n. sp. (abyssal depths, New England to Bermuda transect) and H. guiana n. sp. (bathyal depths off Suriname). Other materials from the Sanders/Hessler North Atlantic collections were also examined and referred to two additional species, H. canariensis n. sp. (deep water off Canary Islands) and H. southwardorum n. sp. (Bay of Biscay) as well as H. cf. reducta from off SW Ireland in bathyal depths. New collections from the North Atlantic region include additional materials of H. hartmanae n. sp. (deep water off the Mid-Atlantic and SE USA), H. aruba n. sp. (Caribbean Sea), H. bathyala n. sp. (deep water off SE USA), and H. dibranchiata n. sp. (deep water, Gulf of Mexico). Heterospio paulolanai n. sp. is from shelf depths off southeastern Brazil. Heterospio knoxi n. sp. is from the North Island of New Zealand, H. ehlersi n. sp. is from the Gulf of Thailand, in the South China Sea, H. bidentata n. sp. is described from deep water in the Coral Sea off eastern Australia, and H. alata n. sp. and H. brunei n. sp. are described from deep water off the Island of Borneo in the South China Sea. Heterospio africana n. sp. and H. antonbruunae n. sp. are described from off east Africa in the Mozambique Channel. New records and descriptions of H. catalinensis, H. indica, and H. peruana are presented. The 15 new species reported here nearly triple the number of previously known species of Heterospio, with 23 species now recognized. All known species are tabulated and compared.

Heterospio knoxi new species Figure 25 urn:lsid:zoobank.org:act: F9CDB736-A633-4022-BB10-0E60017B0E19 Longosoma sp. Knox 1960: 1131. Material examined. Pacific Ocean, New Zealand, North Island, Hawke Bay, coll. Aug 1956, Desmond Hurley, cone grab, 39.388978°S, 177.080489°E, 13–61 m, holotype (LACM-AHF Poly 13320); 1 paratype (LACM-AHF Poly 13290). Description. A large species, both specimens incomplete, but in excellent condition. Holotype (LACM-AHF Poly 13320) with 13 setigers, 26.5 mm long, 1.4 mm wide across thoracic setiger 5; paratype (LACM-AHF Poly 13290) with 12 setigers, 19.6 mm long, 1.3 mm wide across setiger 5. Body long, narrow, divided into thoracic region with first eight setigers crowded and setiger 9 first elongate segment, as long as setigers 6–8 combined (Fig. 25A–B). Thoracic setigers 1–9 dorsoventrally flattened, with low mid-dorsal ridge extending from setiger 3 to 8 (Fig. 25A); mid-ventral ridge present from setiger 3 to anterior border of setiger 9 (Fig. 25B). Abdominal region with elongate cylindrical segments; posterior region not present. Color in alcohol opaque white to light tan. Pre-setiger region short, about as long as setigers 1and 2 (Fig. 25A–B). Prostomium triangular, tapering anteriorly to narrow, rounded tip, posteriorly merging with anterior peristomial ring and continuing posteriorly as a carunclelike dorsal crest overlying second peristomial ring and mid-dorsum of setigers 1–2 (Fig. 25A); eyespots absent; nuchal organs narrow slits between posterior lateral border of prostomium and first peristomial ring. Peristomium entire ventrally, divided into two parts dorsally and laterally; these sections include a narrow, anterior ring separated from prostomium by a curved groove that includes the nuchal organs and a posterior ring separated from the first by a curved groove from which the dorsal tentacles arise (Fig. 25A); tentacles not present on either specimen. Ventral surface of peristomium relatively smooth; mouth a narrow vertical slit with two lateral lobes and posterior lip formed by anterior border of peristomium (Fig. 25B). Branchiae from setigers 2–9; thin when present; others broken or as stubs (Fig. 25A). Individual branchiae with short moniliform-like sections; with internal blood vessel. All parapodia biramous with setal fascicles arising from anterior edge of segment. All thoracic noto- and neuropodia of setigers 1–9 with 40–50 long capillaries in spreading fascicles arising from a cuplike notch; neuropodia with a thickened postsetal lamella or posterior lateral flange-like enlargement on posterior side of setal fascicle (Fig. 25B). Elongate abdominal setigers from setiger 10 with parapodia modified into elongate ridges bearing setae that mostly encircle entire body, leaving only minute dorsal, ventral, and lateral gaps to denote individual noto- and neuropodia (Fig. 25A–B); when spines present, resulting armature resembles that of some cirratulid polychaetes of the genus Chaetozone. Setigers 10–11 with setae all capillaries, those of anterior row thicker and larger than those of posterior row; setiger 12 with anterior row of thicker setae, mostly subuluncini with thickened shaft and thick tapering tip, and a few acicular spines (Fig. 25C–D) and posterior row of slender capillaries; setiger 13 with subuluncini replaced by aristate and acicular spines in about equal numbers in anterior row (Fig. 25E–F) and with posterior row of thin capillaries (Fig. 25G). Remarks. These two specimens of Heterospio (as Longosoma) were donated to the late Dr. Olga Hartman during a visit by the late Dr. George Knox to the Allan Hancock Foundation in 1959; their observations on these specimens and comparison with Dr. Hartman’s H. catalinensis were reported by Knox (1960). The two specimens were originally part of a collection of 27 specimens collected in Aug 1956 from 12 stations in Hawke Bay, consisting of fine sands and muds. Coordinates given here were taken from a mid-point of the Bay since the exact station for these specimens is unknown; however, among the collections of the National Institute of Water & Atmospheric Research Ltd (NIWA), Wellington, New Zealand, nine stations are listed with specimens from this survey. These range in depth from 13 to 61 m (× = 36 ± 12.34); the data indicate that most of the 12 specimens listed have been dry and are in poor condition (G. Reid, personal communication). Heterospio knoxi n. sp. from New Zealand, with branchiae from setigers 2–9, two peristomial rings, setiger 9 being the first elongate setiger, and aristae acicular spines in some abdominal parapodia, most closely resembles H. sinica from the East China Sea (Wu & Chen 1966). The two species differ in that H. knoxi n. sp. has a distinct caruncle-like dorsal crest that extends from the prostomium over the peristomium to the middle of setiger 2, and both aristate and acicular spines are present in setiger 13. In contrast, H. sinica has no peristomial dorsal crest and setigers 13–17 have aristate spines but no acicular ones. See Table 1 for additional information. Methyl Green staining. Anterior half of prostomium and branchiae not stained; stain concentrated on both peristomial rings, dorsal crest and on parapodia, best seen ventrally; rest of body staining uniformly, destaining readily. Biology. The holotype has oocytes in the coelom measuring 145–160 µm in diameter. The habitat of Hawke Bay, New Zealand, where these specimens were collected was reported to consist of grey sands to fine muddy sands with seafloor temperatures ranging from 13.0–13.3°C (Knox 1960). The report of Heterospio sp. by Estcourt (1967) from Marlborough Sound, South Island, NZ, as a dominant species in shallow subtidal benthic assemblages, may be the same as H. knoxi n. sp. Etymology. This species is named for the late Professor George A. Knox (1919–2008), of the University of Canterbury, Christchurch, New Zealand. Professor Knox was a marine ecologist and noted authority on polychaete systematics who identified Heterospio (as Longosoma) in New Zealand and recognized its unusual characteristics (Knox 1960). Distribution. New Zealand, North Island, Hawke Bay, 13– 61 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 51-52, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920, {"references":["Knox, G. A. (1960) The polychaete family Longosomidae in New Zealand. Nature, 187, 1131. [https: // www. nature. com / articles / 1871131 a 0]","Wu, B. L. & Chen, M. (1966) A new and interesting species of the genus Heterospio (Polychaeta, Heterospionidae). Oceanology and Limnology Sinica, 8, 163 - 167.","Estcourt, I. N. (1967) Distributions and associations of benthic invertebrates in a sheltered water soft-bottom environment (Marlborough Sounds), New Zealand. New Zealand Journal of Marine and Freshwater Researc h, 1, 352 - 370. https: // doi. org / 10.1080 / 00288330.1967.9515211"]}

Heterospio southwardorum new species Figure 12 urn:lsid:zoobank.org:act: A65BA064-DF88-44FC-A223-A47C4CDABCC9 Material examined. NE Atlantic Ocean, Bay of Biscay, off Bilbao, Spain, R / V Sarsia, Cruise 5, Sta. 5-56, 19 Jul 1967, coll. A. & E. Southward, EBS, 43.717°N, 03.797°W, 641 m, holotype ( LACM-AHF 13283). Description. A moderately sized species, holotype ( LACM-AHF 13283) incomplete with 13 setigers, 21.3 mm long, 0.43 mm wide across thoracic segments, 0.37 mm wide across middle abdominal segment. Thorax with eight crowded segments followed by elongate setiger 9. Setigers 1–7 twice as wide as long; setiger 8 slightly longer, about as wide as long; setiger 9 greatly elongated, as long as setigers 1–8 combined. Abdominal setigers 10–13 long, narrow, encompassing about 16 mm of total length of holotype. Color in alcohol opaque white to light tan; pigment entirely absent. Pre-setiger region short, as long as first two thoracic setigers (Fig. 12A–B). Prostomium flattened, disklike, broadly rounded anteriorly (Fig. 12A–B); eyespots absent; nuchal organs elongate slits anterior to anterior peristomial ring (Fig. 12A). Peristomium with two rings; first ring narrow, dorsally visible posterior to nuchal organs, not continuing ventrally; second ring large, similar in size and shape to following setigers, interrupted by broad dorsal crest that merges with setiger 1 (Fig. 12A), entire on ventral surface, interrupted by mouth (Fig. 12B). Dorsal tentacles not present, but scars evident in notch between peristomial rings. Mouth a triangular-shaped opening surrounded laterally by thickened lobes (Fig. 12B); proboscis not everted. Branchiae or their stubs present on setigers 2–7 (Fig. 12A); intact branchiae short, oval-shaped. All parapodia biramous with setal fascicles arising from near anterior edge of segment. Thoracic region with eight short setigers (Fig. 12A), each slightly wider than long; setiger 8 slightly longer than those preceding. Setiger 9 elongated, as long as setigers 1–8 combined. All thoracic setigers slightly flattened dorsally with notopodia of setigers 1–7 weakly inflated and elevated over dorsum; notopodia of setigers 8–9 with thickened lobes from which setae arise; neuropodia of setigers 1–9 with short, postsetal lobes (Fig. 12B), most evident on setigers 1–7. Abdominal segments from setiger 10 rounded in cross section with parapodia on anterior borders as transverse ridge encircling body, producing cinctures or rows of setae similar to those of some cirratulids; these ridges interrupted dorsally, ventrally, and laterally denoting location of noto- and neuropodia. All thoracic notopodia of setigers1–9 with 12–16 long capillaries in spreading fascicles; capillaries of neuropodia more numerous, with 25–30 arranged in tight, dense fascicle. Setae of noto- and neuropodia of following setigers in two transverse rows; setigers 10–11 all capillaries, rows with distinct dorsal and lateral gaps; setiger 12 with all capillaries in notopodia and a few acicular spines in anterior row of neuropodia; setiger 13 with cinctures of 10–12 spines in anterior row and 25–30 capillaries (Fig. 12C) in posterior row; capillaries with thin fine tip; spines flattened, tapering to narrow pointed tip, none with aristate tip (Fig. 12D). Posterior bulbous section not present. Methyl Green staining. No pattern, stain not concentrated anywhere along body. Remarks. Heterospio southwardorum n. sp. is most similar to H. mediterranea. Both species have a broad disklike prostomium, two peristomial rings, dorsal peristomial crest, and in both species setiger 9 is the first elongate segment, being as long as setigers 1–8 combined. The two species differ in that in H. southwardorum n. sp. the first peristomial ring is narrow and separated from the prostomium by the nuchal groove, branchiae are present on setigers 2–7, capillary setae are present on setigers 10–11, with acicular spines first present on setigers 12–13, and subuluncini are absent. In contrast, H. mediterranea has both peristomial rings of an equivalent size, branchiae are present on setigers 2–8, and capillary setae are present on setigers 10–12, with acicular spines and subuluncini first present from setiger 13. See Table 1 for further comparison of H. southwardorum n. sp. with its congeners. Etymology. This species is named for the late Drs. Alan and Eve Southward, prominent marine zoologists who directed the R/V Sarsia cruise in the Bay of Biscay during which this species was collected. Dr. Eve Southward was a deep-sea biologist and an authority on annelids of the family Siboglinidae. Distribution. North Atlantic Ocean, Bay of Biscay off Spain, 641 m., Published as part of Blake, James A. & Maciolek, Nancy J., 2023, New species and records of Heterospio (Annelida, Longosomatidae) from continental shelf, slope and abyssal depths of the Atlantic Ocean, Pacific Ocean, Indian Ocean and adjacent seas, pp. 1-74 in Zootaxa 5260 (1) on pages 30-32, DOI: 10.11646/zootaxa.5260.1.1, http://zenodo.org/record/7794920

Two species of genera Apoprionospio and Prionospio are described from the Colombian Caribbean. Apoprionospio sanguarensis sp. nov. and Prionospio gabriellae sp. nov. are new to science. Apoprionospio sanguarensis sp. nov. is distinguished from the three previously described Apoprionospio species by having the smallest body size, triangular prostomium, three pairs of eyes, the branchial pairs 1–3 are cirriform, wrinkled, the anterior notochaetae arranged from chaetiger 2 onwards arranged in three rows, and all hooded hooks lack secondary hoods. Prionospio gabriellae sp. nov. is distinguished from all Prionospio species with five branchial pairs by having dorsal crests across the dorsum on chaetigers 16–25. Closely related species are P. heterobranchia Moore, 1907 and P. caribensis Delgado-Blas, 2014 and Prionospio gabriellae sp. nov. differs from both species in that it has a small medial peak in the dorsal region of prostomium, the first neuropodial lamellae is very small, the shaped of branchial pairs 2 and 3 are cirriform, neuropodial postchaetal lamellae on chaetiger 2 is square, all chaetae of chaetiger 1 are arranged in a row. We propose raising the status of Apoprionospio dayi japonica Imajima, 1989 to the species level as A. japonica Imajima, 1989. A key and a table detailing the most relevant characters of Apoprionospio species and a key to all species of Prionospio with five pairs of branchiae are provided.

Prionospio gabriellae sp. nov. Figures 4A–I; 5A–E Material examined: Caribbean Sea: Sanguaré Natural Reserve, Gulf of Morrosquillo, Sucre (09°42′30.6″N, 75º41´29.0″W), in Thalassia testudinum seaweeds, holotype (CEMUA: ANNE: 002066); Sixty-seven paratypes (CEMUA: ANNE: 002282), colls. Delgado-Blas, VH., Fonseca-González, I., and Londoño-Mesa, MH., June 12 th 2019. Description: Holotype complete, 14.3 mm long for 71 chaetigers, 0.45 mm wide. Color in alcohol opaque white. 8 Paratypes complete 4.3–5.7 mm long, 0.25–0.3 mm wide, with 59–69 chaetigers. 59 Paratypes incomplete 2.4–7.2 mm long, 0.25–0.4 mm wide, with 19–41 chaetigers. Prostomium subtriangular, rounded on anterior margin, with a small medial peak in the dorsal region, tapered posteriorly, with blunt caruncle extending to the posterior edge of chaetiger 2 (Figs 4A, 5A), with large triangular nuchal organs on either side. Two pairs of subdermal black eyes, arranged in a trapezoid; the anterior pair, crescent to rounde in shape (Fig. 5B); the posterior pair, oval and very large (Figs 4A, 5A). Almost all specimens with palps missing, except one specimen with a pair of long palps with heavily scalloped ridges and ciliated groove, without basal sheaths (Fig. 4B), and some ones with regenerated palps (Fig. 4C). Peristomium small, collar-shaped, surrounding the prostomium, fused dorsally with very large rounded notopodial lamellae of chaetiger 1 (Figs 4C, 5C). Neuropodial postchaetal lamellae of chaetiger 1 rounded and very small (Fig. 4C), much smaller than 1/3 the size of the notopodial lamella. Five pairs of long, thick branchiae present on chaetigers 2–6: first and fifth pairs longest, generally first pair longer than fifth (Figs 4C, 5B). All branchiae with thick, tapered tips (Fig. 4C). Pairs 1, 4, and 5 with long, dense digitiform pinnules on the posterior face, and long, naked, smooth, distal tips (Figs 4A, A’, 5B). Pairs 2 and 3 cirriform, with sparsely lateral ciliation and blunt tips (Fig. 4C, D); equal in size, shorter than pinnate pairs, but larger than notopodial lamellae (Fig. 4C). Notopodial postchaetal lamellae foliaceous and wider on chaetigers 2–6 (Figs 4C, D, 5C), lamellae shorter and subtriangular on chaetiger 2, largest on chaetigers 4–6, with blunt tips (Fig. 4C, D); lamellae of chaetigers 7–8 subtriangular, subsequent notopodial lamellae round (Fig. 5C, D), and small on far posterior chaetigers. Chaetigers 2–4 overlapping the ventral and dorsal edges of the noto- and neuropodial lamellae. Notopodial prechaetal lamellae very large in the branchial region, basally fused with notopodial postchaetal lamellae (Figs 4C, 5C), progressively decreasing in size after chaetiger 8, on posterior chaetigers rudimentary. Very low dorsal ridges across the dorsum (Fig. 4E) on chaetigers 8–29, highest on chaetigers 16–25. Neuropodial postchaetal lamellae square on chaetiger 2 (Fig. 4C); all neuropodial lamellae rounded, biggest on chaetiger 3 (Figs 4C, 5C), and small on far posterior chaetigers. Prechaetal lamellae very small (Fig. 4C), rudimentary throughout. Inter-parapodial pouches lacking. Anterior chaetae all capillaries limbate, thin, with long capillary tips (Fig. 4D); anterior row with chaetae slightly granulated and posterior row striated and lacking granulations (Fig. 4F); notopodial and neuropodial capillaries of chaetiger 1 arranged in one rows, with short and thin chaetae, notopodial chaetae longer; from chaetiger 2 onwards arranged in two rows, anterior row shorter than posterior row; chaetae on middle and posterior notopodia arranged in one row, dorsal chaetae very long and ventral chaetae short. Sabre chaetae in neuropodia from chaetigers 12–13 (one specimen in chaetiger 12), one or two per fascicle, robust, very long, moderate granulated, with long tips but no sheaths (Fig. 4G). Neuropodial hooded hooks from chaetigers 13–14, up to eight (5–8) per fascicle, accompanied by up to three capillaries (chaetiger 38) (Fig. 4G). Notopodial hooded hooks from chaetigers 29–43, up to 2 per fascicle, accompanied by capillaries (Fig. 4H); all hooks with four pairs of small teeth above the main tooth and a small secondary hood (Fig. 4G, H). Neuropodial hooks with a small principal hood, and notopodial hooks with large hoods. Pygidium with one long dorso-medial cirrus and two short lateral lobes (Figs 4I, 5E). Etymology. The name of the species is dedicated to the daughter of the second author Gabriela Colorado Fonseca, a sweet young woman, sensitive to nature, who enjoys painting and loves the sea, and is already a little guardian of marine life. Type locality. Caribbean Sea, Sanguaré Natural Reserve, Sucre, Colombia. Remarks: Prionospio gabriellae sp. nov. is distinguished from all other Prionospio species with five branchial pairs by having dorsal crests across the dorsum on chaetigers 16–25. Closely related species are P. heterobranchia Moore, 1907 and P. caribensis Delgado-Blas, 2014 all sharing the following characters with Prionospio gabriellae sp. nov.: dorsal folds on several postbranchial chaetigers, very large notopodial prechaetal lamellae fused with the notopodial postchaetal lamellae, neuropodial postchaetal lamellae of chaetigers 4 and 5 rounded and neuropodial hooded hooks with 4 pairs of teeth. Prionospio gabriellae sp. nov. differs from P. heterobranchia and P. caribensis in that the former has a small medial peak in the dorsal region of prostomium, the first neuropodial lamellae is very small, the shaped of branchial pairs 2 and 3 are cirriform, neuropodial postchaetal lamellae of chaetiger 2 is square, all chaetae of chaetiger 1 are arranged in a row. In addition, P. gabriellae sp. nov. differs from P. heterobranchia in that the former has very low anterior neuropodial prechaetal lamellae.Also, P. gabriellae sp. nov. differs from P. caribensis in that the former has a small peristomium, all the anterior chaetae with granulations and striated, the sabre chaetae appear from chaetigers 12–13, and sabre chaetae are less granulated, and the pygidium having two lateral lobes.

Apoprionospio sanguarensis sp. nov. Figures 2A–G; 3A–C Material examined: Caribbean Sea: Sanguaré Natural Reserve, Gulf of Morrosquillo, Sucre (09°42′30.6″ N, 75º41´29.0″ W), in Thalassia testudinum seaweeds, holotype (CEMUA: ANNE: 002065); three paratypes (CEMUA: ANNE:002281), colls. Delgado-Blas, VH., Fonseca-González, I., and Londoño-Mesa, MH., June 12 th 2019. Description: Holotype complete, 7.9 mm long for 53 chaetigers, 0.3 mm wide. Two paratypes complete, 7.2– 7.3 mm long for 44–58 chaetigers, 0.4 mm wide; one paratype incomplete, 4.5–11 mm long for 28–50 chaetigers, 0.4 mm wide, color in alcohol opaque white. Prostomium triangular, broadly flared, truncate, flattened anteriorly, with a slight wide medial protuberance, tapered posteriorly, with a narrow caruncle ending at base of chaetiger 2 (Figs 2A, 3A). Three pairs of small brown eyes present, arranged in a trapezoid, anterior pair crescent-shaped, widely spaced; posterior pairs small, rounded shaped, closely spaced (Figs 2A, 3A). Peristomium surrounding posterior half of prostomium and clearly separated from chaetiger 1 (Fig. 2A, B). A pair of palps short, extending to chaetiger 2 (Figs 2B, 3A). Branchiae present from chaetiger 2, numbering four pairs; pairs 1–3 cirriform, wrinkled, first pair thinner and smaller than the second and third pair (Fig. 2A); pair of branchiae 2–3 equal in size; branchiae much shorter than notopodial lamellae (holotype), in other specimens, branchiae same size as notopodial lamellae; fourth pair longer, with plate-like pinnules arranged in two rows along the shaft of branchiae, and long, naked, wrinkled, distal tips (Fig. 2A, B). Parapodia of chaetiger 1 with small, oval notopodial postchaetal lamellae and rounded neuropodial postchaetal lamellae (Figs 2B, 3B); neuro-, and notopodial lamellae almost in the same position (Figs 2A, B, 3B). Notopodial postchaetal lamellae foliaceous, wider on chaetigers 2–8, lamellae shorter, thinner, and subtriangular on chaetiger 2, largest on chaetigers 4–6 (Figs 2A, B, 3B), becoming elongate, symmetrical, forming V-shaped cup (Figs 2B, 3B); lamellae of chaetigers 7–8 subtriangular (Fig. 2C), subsequent notopodial lamellae subtriangular and small on far posterior chaetigers (Fig. 3C). Dorsal ridges on the middle and posterior segments absent. Notopodial prechaetal lamellae very large in anterior chaetigers (Figs 2B, 3B), basally fused with notopodial postchaetal lamellae, and subsequent lamellae small in the middle and posterior region. Very low dorsal crest across the dorsum on chaetiger 7 (Fig. 2A). Neuropodial postchaetal lamellae on chaetiger 2 rounded, erect, large (Figs 2A, B, 3B), 2/3 larger than subsequent neuropodial lamellae; following neuropodial postchaetal thinner and bluntly rounded (Figs 2C, 3B), and small on far posterior chaetigers (Fig. 3C). Neuropodial prechaetal lamellae very small in anterior region (Fig. 2B), but rudimentary in middle and posterior chaetigers. Anterior notopodial chaetae heavily granulated, basally striated, thick, long, broadly sheathed capillaries, with long capillary tips (Fig. 2C). Notopodial chaetae longer, thicker, and more broadly sheathed than those of neuropodial chaetae (Fig. 2C). Notopodial capillaries of chaetiger 1 arranged in one row, from chaetiger 2 onwards arranged in three rows up to chaetiger 14, thereafter in one row; anterior row shorter than posterior rows; chaetae dorsal much longer than ventral ones (Fig. 2C). Chaetae on middle and posterior of the body very thin, smooth, long. Neuropodial capillaries chaetae very short, with very long capillary tips, arranged in one row, from chaetiger 2 onwards arranged in two rows; anterior row with chaetae short, smooth, and alimbate, posterior row with chaetae long, granulate and bilimbate (Fig. 2C); neurochaetae on middle and posterior segments very thin, smooth. Sabre chaetae in neuropodia from chaetiger 11, one or two per fascicle; each chaeta robust, very long, striated, moderately granulated, broadly sheathed, with short tips (Fig. 2D). Neuropodial hooded hooks (Fig. 2E) from chaetiger 16, up to 9 per fascicle, accompanied by up to 5 capillaries. Notopodial hooks (Fig. 2F) from chaetiger 33–34, numbering 4–6 per fascicles; hooks with long primary hoods, and secondary hoods absent, with 2–4 small teeth visible in profile above main tooth (Fig. 2E, F). Pygidium with long mid-dorsal and 2 shorter lateral anal cirri (Fig. 2G). Type locality. Caribbean Sea, Sanguaré Natural Reserve, Gulf of Morrosquillo, Sucre, Colombia. Etymology. The species name is referring to the Sanguaré Natural Reserve, whose staff, headed by Alvaro Roldan Maya, has been dedicated to recovering, preserving, and protecting terrestrial and aquatic ecosystems in the Gulf of Morrosquillo, Colombian Caribbean. Remarks. Apoprionospio sanguarensis sp. nov. is distinguished from the three previously described Apoprionospio species by having the smallest body size, triangular prostomium, three pairs of eyes, the branchial pairs 1–3 are cirriform, wrinkled, the post-, and prechaetal notopodial lamellae of chaetigers 1–2 not fused, the anterior notochaetae arranged from chaetiger 2 onwards arranged in three rows, and all hooded hooks lack secondary hoods. Closely related species are A. dayi Foster, 1969, and A. japonica Imajima, 1989 by the presence of a dorsal membranous crest across the dorsum on chaetiger 7. However, Apoprionospio sanguarensis sp. nov. differs from A. dayi and A. japonica in that the former has the notopodial lamellae on chaetiger 2 triangular, the notopodial lamellae on middle and/or posterior chaetiger not forming low ridges approximately level with dorsum. In addition, A. sanguarensis sp. nov. differs from A. dayi in that the former, the peristomium is not fused with chaetiger 1, neuropodial lamellae on chaetiger 2 rounded, and the notochaetae of chaetiger 2 arranged in three rows. Also, A. sanguarensis sp. nov. differs from A. japonica in that the former has smaller branchiae, the branchial pairs 2–3 are cirriform, wrinkled, and the posterior notopodial lamellae without cilia-like tufts along margin. Other differences are described in Table 1., Published as part of Delgado-Blas, Víctor H. & Fonseca-González, Idalyd, 2023, Two new species of spionids from the genera Apoprionospio Foster, 1969 and Prionospio Malmgren, 1867 (Annelida: Spionidae) from the Colombian Caribbean, pp. 158-172 in Zootaxa 5256 (2) on pages 161-163, DOI: 10.11646/zootaxa.5256.2.4, http://zenodo.org/record/7745509, {"references":["Foster, N. M. (1969) New species of spionids (Polychaeta) from the Gulf of Mexico and Caribbean Sea with a partial revision of the genus Prionospio. Proceedings of the Biological Society of Washington, 82, 381 - 400.","Imajima, M. (1989) Spionidae (Annelida, Polychaeta) from Japan 1. The genera Aonides and Apoprionospio. Bulletin of the National Science Museum, Series A (Zoology), 15, 213 - 222."]}

Genus Apoprionospio Foster, 1969 Type species: Apoprionospio dayi Foster, 1969, by original designation. Diagnosis (after Blake et al. 2020, amended): Prostomium subtriangular or wedge-shaped, broad anteriorly, often with medial peak, caruncle extending to end of anterior margin of chaetiger 1; 2–3 pairs of eyes or absent; occipital tentacle lacking. Peristomium reduced, free, or fused with the first chaetiger, surrounding prostomium posteriorly as a collar; lateral wings absent; one pair of densely ciliated palps on frontal surface, palp sheaths absent. Notopodial lamellae of anterior chaetigers lateral rather than dorso-medial. Notopodial prechaetal lamellae very large in anterior chaetigers, basally fused with notopodial postchaetal lamellae, forming a V-shaped cup; the cup does not extend to distal tip of lamella. Dorsal crest or folds on chaetiger 7 present or absent. Neuropodial lamellae enlarged on chaetiger 2. Branchiae from chaetiger 2, numbering four pairs, with pairs 1–3 apinnate triangular or cirriform, pair 4 with flattened, plate-like pinnules. Anterior chaetae all capillaries; multidentate hooded hooks present in posterior noto- and neuropodia; secondary hoods of hooded hooks present or absent; ventral sabre chaetae present. Pygidium with one long dorsomedial cirrus and two shorter ventrolateral lobes. Remarks: Imajima (1989) described Apoprionospio dayi japonica as a new subspecies from Japan after comparing his specimens with the description of A. dayi Foster, 1969 described from North Carolina, USA. Imajima (1989) distinguished A. dayi japonica from A. dayi because the former has the peristomium completely separated rather than fused with chaetiger 1, and the neuropodial lamellae on chaetiger 2 is bluntly rounded, rather than extremely large and triangular with the long axis extending ventrally. We propose that these character differences are sufficient to consider the subspecies as a distinct species. Therefore, we propose raising the status of A. dayi japonica Imajima, 1989 to a full species A. japonica., Published as part of Delgado-Blas, Víctor H. & Fonseca-González, Idalyd, 2023, Two new species of spionids from the genera Apoprionospio Foster, 1969 and Prionospio Malmgren, 1867 (Annelida: Spionidae) from the Colombian Caribbean, pp. 158-172 in Zootaxa 5256 (2) on pages 160-161, DOI: 10.11646/zootaxa.5256.2.4, http://zenodo.org/record/7745509, {"references":["Foster, N. M. (1969) New species of spionids (Polychaeta) from the Gulf of Mexico and Caribbean Sea with a partial revision of the genus Prionospio. Proceedings of the Biological Society of Washington, 82, 381 - 400.","Blake, J. A., Maciolek, N. J. & Meissner, K. (2020) 7.4 Sedentaria: Sabellida / Spionida. In: Purschke, G., Westheide, W. & Boggemann, M. (Eds.), Annelida. Band 2. Pleistoannelida, Sedentaria II. De Gruyter, Berlin and Boston, pp. 1 - 103. https: // doi. org / 10.1515 / 9783110291681 - 001","Imajima, M. (1989) Spionidae (Annelida, Polychaeta) from Japan 1. The genera Aonides and Apoprionospio. Bulletin of the National Science Museum, Series A (Zoology), 15, 213 - 222."]}

Key to known species of Prionospio with five pairs of branchiae (Modified from Delgado-Blas 2014) 1. Dorsal crests or folds on several postbranchial chaetigers..................................................... 2 - Dorsal crests or folds absent............................................................................. 4 2. Prostomium triangular-shaped; anterior neuropodial prechaetal lamellae large............ P. heterobranchia Moore, 1907 - Prostomium bottle-shaped; anterior neuropodial prechaetal lamellae very small.................................... 3 3. Prostomium with small medial peak in dorsal region, neuropodial postchaetal lamellae of chaetiger 1 very small, much smaller than 1/3 the size of the notopodial lamella; branchial pairs 2 and 3 cirriform; low dorsal ridges across the dorsum on chaetigers 8–29; sabre chaetae in neuropodia from chaetigers 12–13……………….......................... P. gabriellae sp. nov. - Prostomium without small medial peak in dorsal region, neuropodial postchaetal lamellae of chaetiger 1 large, almost the same size as the notopodial lamellae; branchial pairs 2 and 3 triangular; low dorsal ridges across the dorsum on chaetigers 7–15; sabre chaetae in neuropodia from chaetigers 14–15..................................... P. caribensis Delgado-Blas, 2014 4. Neuropodial postchaetal lamellae on chaetiger 2 rounded, square or rhomboid; anterior notopodial and neuropodial lamellae overlapping or touching................................................................................ 5 - Neuropodial postchaetal lamellae on chaetiger 2 subrectangular, with dorsally directed process, the lower corners rounded; anterior notopodial and neuropodial lamellae separate............................... P. rosariae Delgado-Blas, 2014 5. Prostomium with a small medial peak on anterior margin; neuropodial lamellae on chaetiger 3 subtriangular; anterior neuropodial prechaetal lamellae large; ventral and dorsal edges of the notopodial and neuropodial lamellae overlapping on chaetigers 2–8; hooks without secondary hoods.................................................... P. newportensis Reish, 1959 - Prostomium without small medial peak; neuropodial lamellae on chaetiger 3 rounded or square; anterior neuropodial prechaetal lamellae short; ventral and dorsal edges of the notopodial and neuropodial lamellae overlapping or touching on chaetigers 2–4; hooks with secondary hoods. …………………………………………...………….. 6 6. Prostomium anteriorly rounded; peristomium long; neuropodial lamellae on chaetiger 2 square or rhomboid; anterior notopodial chaetae not granulated; hooded hooks with 2–3 pairs of teeth................................................... 7 - Prostomium anteriorly truncated; peristomium short; neuropodial lamellae on chaetigers 2–3 rounded; anterior notopodial chaetae granulated; hooded hooks with 4 pairs of teeth.................................... P. texana Hartman, 1951 7. Neuropodial lamellae rhomboid on chaetiger 2 and rounded on chaetiger 3; sabre chaetae without sheaths; hooded hooks with 2–3 pairs of teeth...................................................... P. spongicola Wesenburg-Lund, 1958 - Neuropodial lamellae on chaetigers 2–3 square; sabre chaetae with sheaths; hooded hooks with 3 pairs of teeth................................................................................... P. jamaicensis Delgado-Blas, 2014, Published as part of Delgado-Blas, Víctor H. & Fonseca-González, Idalyd, 2023, Two new species of spionids from the genera Apoprionospio Foster, 1969 and Prionospio Malmgren, 1867 (Annelida: Spionidae) from the Colombian Caribbean, pp. 158-172 in Zootaxa 5256 (2) on pages 169-170, DOI: 10.11646/zootaxa.5256.2.4, http://zenodo.org/record/7745509, {"references":["Delgado-Blas, V. H. (2014) Redescriptions and reestablishments of some species belonging to the genus Prionospio (Polychaeta, Spionidae) and descriptions of three new species. Helgoland Marine Research, 68, 13 - 132. https: // doi. org / 10.1007 / s 10152 - 013 - 0372 - 1","Reish, D. J. (1959) New species of Spionidae (Annelida: Polychaeta) from Southern California. Bulletin of the Southern California Academy of Sciences, 58, 11 - 16.","Hartman, O. (1951) The littoral marine annelids of the Gulf of Mexico. Publications of the Institute of Marine Science, 2, 7 - 124."]}

A new species of the spionid genus Lindaspio Blake & Maciolek, 1992 was collected from a cold seep near the Hainan Island at a depth of 1758 m. Morphologically, Lindaspio polybranchiatasp. nov. differs from the congeners in having a narrow, folded caruncle and more neuropodial branchiae (from chaetiger 20). The 18S, COI, and 16S sequences of the new species have been submitted to GenBank. It is the first record of the genus Lindaspio from Chinese waters. A key to all species of Lindaspio is given.

Boury-Esnault, Nicole, Bellan, Gerard, Bellan-Santini, Denise, Boudouresque, Charles-Francois, Chevaldonné, Pierre, Dias, Alrick, Faget, Daniel, Harmelin, Jean-Georges, Harmelin-Vivien, Mireille, Lejeusne, Christophe, Perez, Thierry, Vacelet, Jean, Verlaque, Marc (2023): The Station Marine d'Endoume, Marseille: 150 years of natural history. Zootaxa 5249 (2): 213-252, DOI: 10.11646/zootaxa.5249.2.3, URL: http://dx.doi.org/10.11646/zootaxa.5249.2.3

A new spionid polychaete, Spio pigmentatasp. nov., is described from the southern and western coasts of Korea. This new species differs from its congeners by the combination of the following morphological characteristics: the presence of orange-brown pigmentation on the anterior part of the prostomium, black pigmentation on the peristomium and along the body, U-shaped nuchal organs, a comparatively long extension of metameric dorsal ciliated organs, three pairs of white dots per chaetiger, two to three posterior abranchiate chaetigers, and the presence of tridentate neuropodial hooded hooks. The partial 16S ribosomal DNA (rDNA) and nuclear 18S rDNA sequences of the new species and Spio sp. 2 reported by Abe and Sato-Okoshi (2021) from Japan showed high similarity, indicating that these two specimens belong to the same species. A detailed description and illustrations of the new species, together with molecular information, are provided.

Este artículo contiene 31 páginas, 19 figuras, 3 tablas., The morphological reexamination of specimens previously identified as Laonice bahusiensis Söderström, 1920 from North European and Mediterranean collections, supported by the molecular analysis of freshly collected material, enabled the recognition of four different species in the region: the genuine L. bahusiensis, L. irinae n. sp. from North European waters, and L. grimaldii n. sp. and L. mediterranea n. sp. from the Mediterranean Sea. The morphology of these species is described and illustrated, and their distributions are clarified based on old and new materials. A key for their identification is also provided. The Bayesian analysis of the COI sequences (483 bp) showed that these four species form a clade, namely the L. bahusiensis species complex, morphologically characterized by the continuous dorsal crests on postbranchiate chaetigers in the adults. The genetic p-distances between the species of the complex ranged from 13.27% to 17.99%, while the intraspecific variability ranged from 0.6% to 1.57%. Together with the sister species Laonice cirrata (Sars, 1851), the L. bahusiensis complex formed the Laonice (Laonice) clade, which is morphologically characterized by the prostomium fused with the anterior peristomial margin. However, the monophyly of the L. bahusiensis complex, as well as that of the clade Laonice (Laonice), needs to be further supported through the analysis of a greater set of genes from a larger number of species.

Dipolydora spinosa sp. nov. http://zoobank.org:act: CE6B878F-E52F-4B92-866F-456FF0FEA34A (Figs 4−10) Type material. South-China Sea, Vietnam, Gulf of Thailand, Phu Quoc Is., 0.5 m, in shell of saddle oyster Placuna ephippium (Philipsson), 3 Feb 1986, MIMB 42712 (paratype). Côn Dao Is., 5 m, in shell of the oyster Lopha cristagalli (Linnaeus), 19 Feb 1986, MIMB 42713 (paratype). Nha Trang Bay: Dung Is., 10 m, in shells of barnacle, Chama sp. and Millepora dichotoma Forsskål, 2 Jun 2006, MIMB 42714 (8 paratypes); Mun Is., 10 m, in hump coral Porites lutea Milne Edwards & Haime, 7 Jun 2006, 42715 (paratype); Dung Is., 10 m, in empty shell of the oyster Lopha cristagalli, 10 Jun 2006, 42716 (paratype); Dung Is., 10 m, in hump coral Porites lutea, 20 Jun 2006, 42717 (18 paratypes); Mun Is., 10 m, in hump coral Porites lutea, 30 Jun 2006, 42718 (21 paratypes); Tre Is., 5 m, in shell of saddle oyster Placuna ephippium, 26 Apr 2021, 42719 (2 paratypes); Tre Is., 3 m, in dead coral encrusted by coralline alga, 30 Apr 2021, 42720 (2 paratypes), 42721 (holotype). Complete data on material examined is provided in Supplementary Table S2. Adult morphology. Adults up to 35 mm long, 1 mm wide for 140 chaetigers. Holotype originally 25 mm long, 0.9 mm wide for 107 chaetigers; anterior and posterior parts fixed in formalin; 35 middle chaetigers fixed in ethanol for molecular analysis. Body light tan in life. Juveniles to about 70-chaetiger stage with remains of larval pigmentation on 15−22 anterior chaetigers, comprising paired dorsal and dorso-lateral melanophores, median dorsal vesiculate melanophores from chaetiger 3, lateral melanophores from chaetiger 2, and small paired ventral melanophores from chaetiger 3; black pigment between eyes, and one pair of melanophores in lateral lips of peristomium (Figs 4A, B, 10D). Prostomium anteriorly bifurcated (Figs 4A, 5A, B), posteriorly extending to middle of chaetiger 5 as a low caruncle, shorter in small individuals (Fig. 6A) (over 1/3 of chaetiger 5 in holotype). Low occipital antenna present on caruncle at level of anterior part of chaetiger 1 (Fig. 7A). One to two small black eyes present in small juveniles; large individuals without eyes. Palps as long as 15−20 chaetigers, with frontal longitudinal groove lined with short cilia, latero-frontal motile compound cilia, short compound non-motile cilia arising directly from palp surface and sparsely scattered on lateral and abfrontal palp surfaces. Chaetiger 1 with capillary chaetae and postchaetal lamellae in both rami; lamellae same as on chaetiger 2; notochaetae as long as but fewer than those on chaetiger 2; neurochaetae shorter than those on chaetiger 2. Juveniles to 30−50-chaetiger stage with only capillary chaetae in posterior notopodia; larger individuals usually with three, occasionally two or four awl-like spines in addition to 1−5 notopodial capillaries in a tuft from chaetigers 28−52 (Figs 6B, 7 E−H, 8K, L). Spines almost straight, with distal end slightly protruding out of body wall, smooth surface and basal end blunt (Fig. 8K). Chaetiger 5 twice as large as chaetigers 4 and 6, on each side with up to six geniculate dorsal superior capillaries (Fig. 8F), six falcate spines alternating with bilimbate-tipped companion chaetae (Fig. 8 A−D) and arranged in oblique slightly curved row, and six ventral capillaries (Fig. 8E). Dorsal superior and ventral capillaries winged, shorter and fewer than those chaetae on chaetigers 4 and 6. Falcate spines with spoon-like hollow on subdistal concave side and narrow transverse shelf on subdistal convex side (Fig. 8B, D); transverse shelf apparently worn and therefore not seen on spines of some individuals. Hooded hooks in neuropodia from chaetiger 7, up to six in a series, accompanied by 1−2 inferior winged capillaries (Fig. 8G) until chaetigers 10−12, and alternating with 1−2 hair-like alimbate capillaries (Fig. 8I) in 3−10 posterior neuropodia. Hooks bidentate, with slightly curved shaft without constriction (Fig. 8H, J). Branchiae usually from chaetiger 8 (on chaetigers 8−88 in holotype), occasionally from chaetiger 9 (3 of 26 examined paratypes), full-sized from chaetigers 10−11, absent from posterior 1/3−1/4 part of body (Fig. 6B), free from notopodial postchaetal lamellae, flattened, with surfaces oriented parallel to body axis. Nototrochs in juveniles and females from chaetigers 9−13, in males from chaetiger 1, all composed by single rows of ciliated cells. Intersegmental transverse ciliation present on anterior chaetigers in males as single rows of ciliated cells along anterior edge of chaetigers, from chaetiger 2 to chaetigers 10−12. Pygidium fleshy, cup-shaped with dorsal gap to incision, white due to numerous fusiform glandular cells (Figs 7 E−G, 9A). Glandular pouches in neuropodia from chaetiger 6, large from chaetiger 7 to chaetigers 10−12 and then gradually diminishing in size. Digestive tract with gizzard-like structure beginning from chaetigers 13−29 (from chaetiger 21 in holotype) and extending through 1−2 chaetigers (Figs 5C, 6A). Gizzard composed of anterior transparent muscular part and posterior white, apparently secretory, part. Some grain-like structures present in wall of muscular part of some individuals (Fig. 5D; these may represent fragmented “teeth” of the gizzard as discussed in Blake 1971, Fig. 14g therein). Rectum white in 5−15 posterior most chaetigers. Nephridia from chaetiger 7, opening to exterior via two nephridiopores situated on lateral sides in anterior sterile chaetigers and on dorsal side in fertile chaetigers (Fig. 10E). MG staining. Paired blotches (gatherings of strongly stained, probably glandular, cells) appeared on the dorsal side from chaetigers 12–17 onwards (Fig. 10A, B, E), except 10−30 posterior most chaetigers. Narrow transverse bands were weakly stained on the ventral side from chaetiger 7 to chaetigers 10–12 (Fig. 10C). Prostomium and the peristomium did not absorb the dye, but the foregut was evenly colored (Fig. 10C, D). Habitat. Dipolydora spinosa sp. nov. is an opportunistic borer, making U-shaped burrows in shells of the saddle oyster Placuna ephippium, cockscomb oyster Lopha cristagalli (Linnaeus), jewel box clam Chama sp., barnacles, in the hump coral Porites lutea Milne Edwards & Haime, and the net fire coral Millepora dichotoma Forsskål. Up to three worms were found per one square cm of coral surface and hundreds of worms were occasionally present in corals of about 20 cm in diameter. Reproduction. Dipolydora spinosa sp. nov. is dioecious. Paired gonads are attached to segmental blood vessels from chaetigers 23−42 to chaetigers 50−82 (n=15) (Fig. 9A). Smallest mature individuals were about 17 mm long for 70 chaetigers. Holotype is a female with oocytes in chaetigers 28−82. Oogenesis is mainly intraovarian. Developed oocytes accumulate in the coelomic cavity prior to spawning. The coelomic oocytes were subspherical to slightly oval, 100−115 µm in diameter. In males, spermatogonia proliferate in testes; spermatogenesis occurs in the coelomic cavity. Spermatids are joined in octads (Fig. 8M). Spermatozoa are introsperm about 1 µm in diameter, with a pointed acrosome 1.5 µm long, nucleus 7.5 µm, middlepiece 6 µm, head+middlepiece 15 µm long, and flagellum 50 µm long. A small colony of about 20 individuals in the hump coral Porites sp. collected from Nha Trang Bay in June 2006 contained only males. One of them had seven chaetigers regenerating anteriorly, middle stock chaetigers, and a few chaetigers regenerating posteriorly; regenerating chaetigers were slightly smaller and more transparent than fully developed stock chaetigers. This colony likely appears to have developed due to asexual reproduction by architomy from a single settled larva of male gender. It seems likely that after settlement, individuals first undergo a series of architomic divisions and only after that mature and start reproducing sexually. Such colony formation has been found in other polydorin species that exhibit architomy (Radashevsky, pers. obs.) and will be the subject of future studies. Larval development. Females lay eggs into transparent capsules which join to each other in a string and each attach by two short stalks to the inner wall of the burrow (Fig. 9C). Up to 60 eggs were deposited in one capsule and up to 55 capsules with about 3000 eggs were produced by one female per brood; small females had smaller broods. The laid eggs were 105−120 µm in diameter, with smooth envelope less than 1 µm thick. Females brooding larvae in capsules had the next generation of vitellogenic oocytes developing in the ovaries. Most of the eggs in the broods developed into larvae, but about 10% of eggs were abortive (it is not known whether these result from sperm limitation or represent nurse egg development; see Smith & Gibson 1999). The egg capsules with trochophores and abortive eggs were found in Nha Trang Bay in June 2006 (Fig. 9C, D). The trochophores had a few very small trochoblasts bearing short cilia of the prototroch, and one pair of rounded ventral ciliary patches. They had no eyes and moved inside capsules due to active beating of the ciliary patches. The larvae had a small mouth and a short foregut lined with numerous fine cilia (Fig. 9D). The posterior end of the foregut was joined to a spherical mass of large yolky endodermal macromeres occupying most of the inner space of larvae. Lumen of midgut, posterior gut, and anus were not yet developed. The duration of larval development inside the capsules remains unknown, but compared to other polydorins producing similar broods (see Blake & Arnofsky 1999), D. spinosa sp. nov. larvae probably hatch after growing 3−5 chaetigers. Remarks. By having an occipital antenna on the prostomium, D. spinosa sp. nov. is similar to D. tentaculata (Blake & Kudenov, 1978) from New South Wales, Australia, and D. anatentaculata Delgado-Blas, 2008 from the Gulf of Mexico, Florida. Dipolydora spinosa sp. nov. and D. tentaculata have caruncles of similar maximal length, extending to the middle of chaetiger 5 (for D. anatentaculata, Delgado-Blas 2008: 8, fig. 2A described the “caruncle extending posteriorly to segment 4” but illustrated it as reaching chaetiger 5). Dipolydora spinosa sp. nov. has a cup-shaped pygidium with only dorsal incision (which is comparatively rare among Dipolydora spp. that mainly have lobate pygidia with three or four lobes) while the pygidial shapes are unknown for D. tentaculata and D. anatentaculata. Dipolydora spinosa sp. nov. and D. anatentaculata are shell-borers while D. tentaculata lives in tubes in sediment. Dipolydora spinosa sp. nov. differs from these two species in the structure of the falcate spines of chaetiger 5. In D. tentaculata and D. anatentaculata, the spines are simple, without accessory structures, whereas in D. spinosa sp. nov. the spines have a spoon-like hollow on the concave side and a narrow transverse shelf on the convex side. Blake & Kudenov (1978: 250) noted that in D. tentaculata the notochaetae of the posterior chaetigers “including long slender capillaries and a stouter spine.” On the illustration (Blake & Kudenov 1978: fig. 39c), however, the chaeta resembles thick anterior-row capillary notochaeta rather than a genuine spine (see Discussion below). Adults of D. spinosa sp. nov. have 2−4 (usually three) awl-like spines in addition to 1−5 capillaries in a tuft in the posterior notopodia; the spines are almost straight, with basal end blunt. Etymology. The species name, feminine for Latin spinosus (spiny, thorny), refers to the awl-like spines in the posterior notopodia of adults. Distribution. South-China Sea, Vietnam (see Table S2, Fig. 1A, B)., Published as part of Radashevsky, Vasily I., 2022, Three new species of shell-boring Dipolydora (Annelida: Spionidae: Polydorini) from the South China Sea and the Gulf of Thailand, Vietnam, with comments on the modified spines in posterior notopodia and sperm morphology in polydorins, pp. 101-119 in Zootaxa 5162 (2) on pages 106-111, DOI: 10.11646/zootaxa.5162.2.1, http://zenodo.org/record/6809879, {"references":["Blake, J. A. (1971) Revision of the genus Polydora from the east coast of North America (Polychaeta: Spionidae). Smithsonian Contributions to Zoology, 75, 1 - 32.","Smith, H. L. & Gibson, G. D. (1999) Nurse egg origin in the polychaete Boccardia proboscidea (Spionidae). Invertebrate Reproduction and Development, 35 (3), 177 - 185. https: // doi. org / 10.1080 / 07924259.1999.9652384","Blake, J. A. & Arnofsky, P. L. (1999) Reproduction and larval development of the spioniform Polychaeta with application to systematics and phylogeny. Hydrobiologia, 402, 57 - 106. https: // doi. org / 10.1023 / A: 1003784324125","Blake, J. A. & Kudenov, J. D. (1978) The Spionidae (Polychaeta) from southeastern Australia and adjacent areas with a revision of the genera. Memoirs of the National Museum of Victoria, 39, 171 - 280.","Delgado-Blas, V. H. (2008) Polydora and related genera (Polychaeta: Spionidae) from the Grand Caribbean region. Journal of Natural History, London, 42 (1 - 2), 1 - 19. https: // doi. org / 10.1080 / 00222930701831240"]}

Radashevsky, Vasily I. (2022): Three new species of shell-boring Dipolydora (Annelida: Spionidae: Polydorini) from the South China Sea and the Gulf of Thailand, Vietnam, with comments on the modified spines in posterior notopodia and sperm morphology in polydorins. Zootaxa 5162 (2): 101-119, DOI: https://doi.org/10.11646/zootaxa.5162.2.1

Dipolydora echinata sp. nov. http://zoobank.org:act: E9F81CFA-BD86-433A-A1AF-7BC235544D5D (Figs 2 & 3) Type material. South China Sea, Vietnam, Nha Trang Bay: Dung Is., 10 m, in shell of jewel box clam Chama sp., 19 May 2006, MIMB 42700 (paratype); Tam Is., 10 m, in fire coral Millepora platyphylla Hemprich & Ehrenberg, 22 May 2006, MIMB 42701 (2 paratypes); Dung Is., 10 m, in shell of saddle oyster Placuna ephippium (Philipsson), 10 Jun 2006, MIMB 42702 (holotype). Complete data on material examined is provided in Supplementary Table S1. Adult morphology. Adults up to 20 mm long, 0.4 mm wide for 116 chaetigers; holotype 15 mm long, 0.3 mm wide for 113 chaetigers. Body light tan in life; distinct pigmentation absent. Prostomium bifurcated anteriorly, with shallow transverse fissure at level of chaetiger 1 separating narrow posterior caruncle extending to end of chaetiger 3 (Fig. 2A); caruncle shorter in small individuals. Anterior part of caruncle, just behind fissure, inflated, but occipital antenna absent. Eyes absent. Palps as long as 15−20 chaetigers, with frontal longitudinal groove lined with short cilia, latero-frontal motile compound cilia, and short compound non-motile cilia arising directly from palp surface and scattered on lateral and abfrontal palp surfaces. Chaetiger 1 with short capillaries and small postchaetal lamellae in both rami. Posterior notopodia (from chaetiger 36 in holotype) with up to six awl-like spines in addition to 1−5 slender capillaries in a tuft (Figs 2 M−O, 3A, B). In live individuals, spines entirely embedded into body; in fixed specimens, distal tips often slightly protruding out of notopodia. Distal ends of spines pointed and slightly curved. Partially developed spines with basal end truncate (Fig. 2M); fully developed spines double-edged, with basal and distal ends pointed (Fig. 2N). Chaetiger 5 larger than chaetigers 4 and 6, on each side with up to four geniculate dorsal superior capillaries (Fig. 2H), six heavy falcate spines alternating with bilimbate-tipped companion chaetae (Fig. 2 B−F) and arranged in an oblique slightly curved row, and seven ventral capillaries (Fig. 2G). Dorsal superior and ventral capillaries winged, shorter than those chaetae on chaetigers 4 and 6. Falcate spines with thin transverse subdistal collar on convex and lateral sides; lateral parts of collar usually prominent, resembling small lateral teeth or spurs (Fig. 2C, E, F). Hooded hooks in neuropodia from chaetiger 7, up to seven in a series, accompanied by 1−2 inferior winged capillaries (Fig. 2I) until chaetigers 8−10, and alternating with 1−2 hair-like alimbate capillaries (Fig. 2K) in 10−20 posterior neuropodia. Hooks bidentate, with slightly curved shaft without constriction; upper tooth well developed, at about right angle to main fang in anterior neuropodia (Fig. 2J), greatly reduced and closely applied to main fang in posterior neuropodia (Fig. 2L). Branchiae from chaetiger 7 to chaetiger 50 in 113-chaetiger holotype, to chaetiger 37 in a 85-chaetiger individual, and to chaetiger 42 in a 116-chaetiger individual; full-sized from chaetigers 11−14, free from notopodial postchaetal lamellae, flattened, with surfaces oriented parallel to body axis. Of two paratypes (MIMB 42701), one individual with branchiae from chaetiger 9, and another with branchiae from chaetiger 10. In these worms, first ten anterior chaetigers slightly smaller than succeeding chaetigers, suggesting recent regeneration likely after asexual reproduction by architomy or after a partial predation event. Branchiae from chaetiger 9 or 10 also in some other examined but not fixed individuals. Nototrochs from chaetigers 9−13, composed of single rows of ciliated cells. Intersegmental ciliation absent. Pygidium cup-shaped, with dorsal gap to incision, white due to numerous fusiform glandular cells (Fig. 3A, C). Glandular pouches in neuropodia from chaetiger 7, full-sized from chaetigers 7−8 and diminishing in size after chaetigers 10−15. Digestive tract with gizzard-like structure beginning from chaetigers 16−21 and extending through 1−2 chaetigers. Gizzard composed of anterior transparent muscular part and posterior white, apparently secretory, part. Rectum white in 3−5 posterior most chaetigers. Nephridia from chaetiger 7, opening to exterior via two nephridiopores situated on lateral sides in anterior sterile chaetigers and on dorsal side in fertile chaetigers. Habitat. Dipolydora echinata sp. nov. is an opportunistic borer, making U-shaped burrows in shells of the saddle oyster Placuna ephippium (Philipsson), razor clam Pinna cf. bicolor Gmelin, jewel box clam Chama sp., vase snail Vasum turbinellus (Linnaeus), spindle snail Polygona infundibulum (Gmelin) occupied by hermit crab, in fire coral Millepora platyphylla Hemprich & Ehrenberg, and under crust of coralline algae on shells of the penguin’s wing oyster Pteria penguin (Röding). Reproduction. Two mature individuals (holotype and a not fixed specimen) were males with sperm from chaetiger 38 through most of the body. Spermatogonia proliferated in testes; spermatogenesis occurred in the coelomic cavity. Spermatids were joined in tetrads (Fig. 2P). Spermatozoa were introsperm with elongated straight head about 1 µm in diameter, head+middlepiece 12 µm long, acrosome 3 µm, nucleus 5 µm, middlepiece 4 µm, and flagellum 38 µm long. Egg morphology and larval development of the species remain unknown. Remarks. Dipolydora echinata sp. nov. co-occurs in shells with D. spinosa sp. nov. (see below). Both species have bifurcated prostomia, awl-like spines in the posterior notopodia, and cup-shaped pygidia with only dorsal incision. They differ in that D. echinata sp. nov. has no occipital antenna, caruncle extending to the end of chaetiger 3, branchiae beginning on chaetiger 7, awl-like spines in the posterior notopodia double-edged, up to six in a series, and spermatids joined in tetrads, while D. spinosa sp. nov. has an occipital antenna, caruncle extending to the middle of chaetiger 5, branchiae beginning on chaetigers 8−9, awl-like spines in the posterior notopodia with basal part blunt, up to three in a series, and spermatids joined in octads. Moreover, D. spinosa sp. nov. has chaetiger 5 falcate spines with spoon-like hollow on subdistal concave side and a thin transverse shelf on convex side, while spines of D. echinata sp. nov. have no spoon-like hollow on concave side and have a wide collar on convex side with lateral parts prominent, resembling small teeth or spurs. By having a cup-shaped pygidium with only dorsal incision, D. echinata sp. nov. is similar to D. protuberata (Blake & Kudenov, 1978) from Victoria, Australia, and D. pilikia (Ward, 1981) from Hawaii. The species differ in that D. echinata sp. nov. has caruncle extending to the end of chaetiger 3, branchiae beginning on chaetiger 7 and lacking from the posterior half of the body, and chaetiger 5 falcate spines with transverse subdistal collar with lateral parts prominent, resembling small teeth or spurs, while D. protuberata and D. pilikia have caruncles extending beyond chaetiger 3, branchiae beginning on chaetigers 8−9 and continuing beyond the middle of the body, and chaetiger 5 falcate spines with a subterminal protuberance. Blake & Kudenov (1978: 250) and Ward (1981: 724) noted that D. protuberata and D. pilikia have “short acicular spines” in addition to capillaries in the posterior notopodia. These spines, however, were not illustrated for D. pilikia. Ward (1987: 354) also noted about D. pilikia: “This very common bioeroder in coral rock … has been collected from coral rock, coral sediment blocks, and sediment in Kaneohe Bay, from sand and rubble on the reef flat at Fort Kamehameha, and from sediment in Pearl Harbor, Oahu.” This description may be interpreted as some worms were living in tubes in soft sediments while others bored into corals. Dipolydora pilikia has never been redescribed and not reported again from Hawaii. Dipolydora protuberata was found only in tubes in soft sediments while D. echinata sp. nov. was found only in burrows in mollusc shells. Etymology. The species name, feminine for Latin echinatus (echinate, prickly), refers to the awl-like spines in the posterior notopodia of adults. Distribution. South-China Sea, Vietnam (see Table S1, Fig. 1A, B)., Published as part of Radashevsky, Vasily I., 2022, Three new species of shell-boring Dipolydora (Annelida: Spionidae: Polydorini) from the South China Sea and the Gulf of Thailand, Vietnam, with comments on the modified spines in posterior notopodia and sperm morphology in polydorins, pp. 101-119 in Zootaxa 5162 (2) on pages 103-105, DOI: 10.11646/zootaxa.5162.2.1, http://zenodo.org/record/6809879, {"references":["Blake, J. A. & Kudenov, J. D. (1978) The Spionidae (Polychaeta) from southeastern Australia and adjacent areas with a revision of the genera. Memoirs of the National Museum of Victoria, 39, 171 - 280.","Ward, L. A. (1981) Spionidae (Polychaeta: Annelida) from Hawaii, with descriptions of five new species. Proceedings of the Biological Society of Washington, 94 (3), 713 - 730.","Ward, L. A. (1987) Family Spionidae. In: Devaney, D. M. & Eldredge, L. G. (Eds.), Bailey-Brock, J. H., Phylum Annelida. Bishop Museum Press, Honolulu, pp. 340 - 369."]}

Dipolydora vietnamita sp. nov. http://zoobank.org:act: EB418B1C-0919-4E41-AAF0-624C42743768 (Figs 11−14) Type material. South-China Sea, Vietnam, Gulf of Thailand, An Thoi Archipelago, Thom Is., 5 m, in shell of the gastropod Vasum turbinellus (Linnaeus) occupied by hermit crab, 4 Feb 1986, MIMB 42722 (paratype). Nha Trang Bay: Tam Is., 10 m, in dead coral encrusted by coralline alga, 22 May 2006, MIMB 42723 (4 paratypes); Dung Is., 10 m, in shell of Chama sp., 2 Jun 2006, MIMB 42724 (26 paratypes); Tre Is., eastern side, 15 m, in dead coral, 14 Jun 2006, MIMB 42725 (40 paratypes), 42726 (holotype); Nha Trang, pier fouling, 3 m, in coral on pillar, 11 Jul 2006, MIMB 42727 (25 paratypes); under crust of coralline alga on shell of Arca avellana Lamarck bought in Nha Trang market, 30 Apr 2021, MIMB 42728 (5 paratypes); in oyster shell bought in Nha Trang market, 30 Apr 2021, MIMB 42729 (paratype). Complete data on material examined is provided in Supplementary Table S3. Adult morphology. Adults up to 21 mm long, 0.55 mm wide for 125 chaetigers. Pigmentation absent on body; some individuals with fine black pigment diffused on sides of palp grooves. Prostomium anteriorly bifurcated, posteriorly extending to end of chaetiger 4 as a low caruncle, shorter in small individuals (Figs 11A, 12A). Eyes and occipital antenna absent. Palps as long as 15−20 chaetigers, with frontal longitudinal groove lined with fine cilia, latero-frontal motile compound cilia on sides of groove, short compound non-motile cilia arising directly from palp surface and scattered on lateral and abfrontal palp surfaces. Chaetiger 1 with short capillaries and small postchaetal lamellae in both rami. Posterior notopodia with only capillary chaetae. Chaetiger 5 larger than chaetigers 4 and 6, with up to five dorsal superior capillaries (Fig. 13F), five falcate spines alternating with bilimbate-tipped companion chaetae (Fig. 13 A−D) and arranged in oblique slightly curved row, and six ventral capillaries (Fig. 13E). Dorsal superior and ventral capillaries winged, shorter and fewer than those chaetae on chaetigers 4 and 6. Falcate spines with spoon-like hollow on subdistal concave side (Fig. 13B, D). Hooded hooks in neuropodia from chaetiger 7, up to five in a series, accompanied by 1−2 winged inferior capillaries until chaetigers 9−10 (Fig. 13G), and alternating with 1−2 hair-like alimbate capillaries in 5−10 posterior neuropodia (Fig. 13I). Hooks bidentate, with slightly curved shaft without constriction. Branchiae usually from chaetiger 9, occasionally from chaetigers 8 or 10, full-sized from chaetigers 12−14, very short after middle of body and absent from posterior 1/3−1/8 part of body (Fig. 12B), free from notopodial postchaetal lamellae, flattened, with surfaces oriented parallel to body axis. Nototrochs from chaetigers 6−7 in small individuals with up to about 40 chaetigers, from chaetigers 10−16 in larger worms, composed of single rows of ciliated cells in both sexes. Intersegmental ciliation absent. Pygidium usually thin, flaring, disc-like to cup-shaped, up to two times wider than posterior most chaetigers, trilobed, with one ventral lobe and two smaller dorsal lobes, white due to numerous fusiform glandular cells. Lateral clefts shallow and indistinct in some individuals, thus pygidium resembling a cup or a disc with only dorsal incision (Fig. 11D, E). Glandular pouches in neuropodia from chaetiger 6, full-sized from chaetigers 7−8, diminishing in size after chaetigers 10−13. Digestive tract with gizzard-like structure beginning from chaetigers 9−18 (Fig. 12A) and extending through 1−2 chaetigers. Gizzard composed of anterior transparent muscular part and posterior white, apparently secretory, part. Rectum white in 3−5 posterior most chaetigers. Nephridia from chaetiger 7, opening to exterior via two nephridiopores situated on lateral sides in anterior sterile chaetigers and on dorsal side in fertile chaetigers. MG staining. Weak staining appeared on the lateral and ventral sides of the peristomium; the foregut was evenly colored (Fig. 11F, G). Paired blotches (gatherings of strongly stained, probably glandular, cells) appeared on the dorsal side from chaetigers 19–22 onwards (Fig. 11C, F), except 10−20 posterior most chaetigers. Narrow transverse bands were weakly stained on the ventral side of chaetigers 6 and 11; wider bands of stronger staining were present on chaetigers 8–10 (Fig. 11B). In most specimens, peristomium and ventral side of chaetigers 6 and 11 were not stained, whereas in some specimens the dye was not absorbed on the ventral side of anterior chaetigers. In 20 of 21 stained specimens, the prostomium and about 20 anterior chaetigers did not absorb the dye (Fig. 11F), whereas in one specimen intense staining appeared on the dorsal side of prostomium and eight anterior chaetigers (Fig. 11A). Glandular pouches in neuropodia absorbed the dye and were well seen in lateral view from chaetigers 8−11 to chaetigers 25−30 (Fig. 11G). Habitat. Dipolydora vietnamita sp. nov. is an opportunistic borer, making burrows in corals, coralline algae, shells of the jewel box clam Chama sp., hazelnut ark Arca avellana Lamarck, and vase snail Vasum turbinellus (Linnaeus) occupied by hermit crabs. This species is common in the coastal waters of Vietnam, co-occurring with other shell-boring polydorins in the same shells and corals. Sometimes the worms occur in dense aggregations up to ten individuals per square centimeter, forming colonies of hundreds of worms in one shell and thousands of worms in a coral. Two worms were found boring in a shell of the date mussel Lithophaga sp. which, in turn, perforated the shell of the hazelnut ark Arca avellana (Fig. 14 A−C). Reproduction. Dipolydora vietnamita sp. nov. is dioecious. Paired gonads are attached to segmental blood vessels from chaetigers 21−24 through 2/3−3/4 of the body. Spermatogonia proliferate in testes; spermatogenesis occurs in the coelomic cavity. Spermatids are joined in tetrads (Fig. 13K). Spermatozoa are introsperm about 1 µm in diameter, with a pointed acrosome 3 µm long, nucleus 5 µm, middlepiece 4 µm, head+middlepiece 12 µm long, and flagellum 54 µm long. Egg morphology and larval development of the species remain unknown. Asexual reproduction. Many fragments of worms regenerating anterior and posterior chaetigers were found in shells from Nha Trang Bay in June 2006. Examination of those fragments has allowed for determining the course of the architomic asexual reproduction of D. vietnamita sp. nov. In the beginning, individuals divide into two or three stock fragments, each of which subsequently regenerates lost parts. The smallest stock fragment had six middle chaetigers. The anterior regeneration starts with a bud that grows and differentiates into head and body anlage. Palps begin to develop immediately after head differentiation. The body anlage elongates gradually and becomes segmented, probably simultaneously, into eight segments; no more segments are added anteriorly. Chaetae, postchaetal lamellae and other external segment attributes, as well as mouth and foregut, develop only when the segmentation is completed. Eyes never develop in the regenerated head. The posterior regeneration also starts with a bud that gives rise to the pygidium and the pre-pygidial growth zone. New posterior stolon segments develop successively following the formation of the growth zone. Similar records of architomy have been found in other spionids such as Pygospio elegans Claparède, 1863 (Rasmussen 1953) and Dipolydora armata (Radashevsky & Nogueira 2003). Remarks. Dipolydora vietnamita sp. nov. is similar to D. socialis (Schmarda, 1861) from Chile, and D. protuberata from New South Wales, Australia, by having subdistal protuberance on the falcate spines of chaetiger 5. However, the two latter species are tube-dwellers in soft sediments while D. vietnamita sp. nov. is a shell- and coral-borer. Dipolydora vietnamita sp. nov. and D. socialis have trilobed pygidia but differ in the arrangement of branchiae and composition of the gizzard-like structures. Dipolydora socialis has branchiae usually beginning from chaetiger 8 and gizzard with four chitinous plates attached to the inner wall of muscular part, while D. vietnamita sp. nov. has branchiae usually beginning from chaetiger 9 and gizzard without chitinous plates. Dipolydora vietnamita sp. nov. differs from D. protuberata by having trilobed pygidium instead of disc-like pygidium with a dorsal notch. Etymology. The species name refers to the type locality of the species in Vietnam. Distribution. South-China Sea, Vietnam (see Table S3, Fig. 1A, B)., Published as part of Radashevsky, Vasily I., 2022, Three new species of shell-boring Dipolydora (Annelida: Spionidae: Polydorini) from the South China Sea and the Gulf of Thailand, Vietnam, with comments on the modified spines in posterior notopodia and sperm morphology in polydorins, pp. 101-119 in Zootaxa 5162 (2) on pages 112-115, DOI: 10.11646/zootaxa.5162.2.1, http://zenodo.org/record/6809879, {"references":["Claparede, E. (1863) Beobachtungen uber Anatomie und Entwicklungsgeschichte wirbelloser Thiere an der Kuste von Normandie Angestellt. Wilhelm Engelmann, Leipzig, vii + 120 pp.","Rasmussen, E. (1953) Asexual reproduction in Pygospio elegans Claparede (Polychaeta sedentaria). Nature, 171, 1161.","Radashevsky, V. I. & Nogueira, J. M. M. (2003) Life history, morphology and distribution of Dipolydora armata (Polychaeta: Spionidae). Journal of the Marine Biological Association of the United Kingdom, 83 (2), 375 - 384. https: // doi. org / 10.1017 / S 0025315403007227 h","Schmarda, L. K. (1861) Neue wirbellose Thiere beobachtet und gesammelt auf einer Reise um die Erde 1853 bis 1857. Erster Band. Turbellarien, Rotatorien und Anneliden. Zweite Halfte. Verlag von Wilhelm Engelmann, Leipzig, 164 pp."]}

Polydora tunicola Abe, Hoshino & Yamada, sp. nov., a new spionid species currently considered an obligate symbiont of styelid ascidians, is described based on materials collected from Polycarpa cf. cryptocarpa kroboja (Oka, 1906) and Cnemidocarpa sp. in Izu-Oshima Island and Polycarpa sp. in Wakayama Prefecture, Japan. Polychaete–ascidian symbiotic relationships are known only in two syllid species: Myrianida pinnigera (Montagu, 1808) and Proceraea exoryxae Martin, Nygren & Cruz-Rivera, 2017. The latter has been the only polychaete known to bore into the tunic of an ascidian. Polydora tunicola sp. nov. is the second known example of a tunic-boring polychaete, which constructs U-shaped burrows in the tunic of the host ascidians. Worms were often concentrated near the host siphons and assumed to use water currents created by the filter-feeding host for suspension feeding. Although the boring mechanism into ascidian tunica is unknown, the plate assay and zymography results consistently detected cellulase activities, suggesting that cellulose digestion may enable the worms to bore into the cellulose-rich ascidian tunics. Polydora tunicola sp. nov. is morphologically similar to P. aura Sato-Okoshi, 1998, P. cornuta Bosc, 1802, P. fusca Radashevsky & Hsieh, 2000, P. glycymerica Radashevsky, 1993, P. latispinosa Blake & Kudenov, 1978, P. lingulicola Abe & Sato-Okoshi, 2020, P. nanomon Orensky & Williams, 2009, P. robi Williams, 2000, and P. vulgaris Mohammad, 1972 in having a single median antenna on the caruncle and chaetiger 5 without dorsal superior capillaries but with ventral capillaries. The new species is unique in having a black-rimmed pygidium, distinguishing it from these species. The phylogenetic analyses of the concatenated 18S, 28S, and 16S sequences recovered P. tunicola sp. nov. as the sister species to P. aura within a well-supported clade also including P. lingulicola and P. cf. glycymerica. The bright yellow body color of P. tunicola sp. nov. in life is similar to that of P. aura, however, these two species are distinguished by the former not having modified posterior notochaetae. The symbiotic nature of the association between P. tunicola sp. nov. and styelid ascidians is discussed.

Planktonic larvae of spionid polychaetes are among the most common and abundant group in coastal meroplankton worldwide. The present study reports the morphology of spionid larvae collected mainly from coastal waters of northeastern Japan that were identified by the comparison of adult and larval 18S and 16S rRNA gene sequences. The molecular analysis effectively discriminated the species. Adult sequences of 48 species from 14 genera (Aonides Claparède, 1864; Boccardia Carazzi, 1893; Boccardiella Blake & Kudenov, 1978; Dipolydora Verrill, 1881; Laonice Malmgren, 1867; Malacoceros Quatrefages, 1843; Paraprionospio Caullery, 1914; Polydora Bosc, 1802; Prionospio Malmgren, 1867; Pseudopolydora Czerniavsky, 1881; Rhynchospio Hartman, 1936; Scolelepis Blainville, 1828; Spio Fabricius, 1785; Spiophanes Grube, 1860) and larval sequences of 41 species from 14 genera (Aonides; Boccardia; Boccardiella; Dipolydora; Laonice; Paraprionospio; Poecilochaetus Claparède in Ehlers, 1875; Polydora; Prionospio; Pseudopolydora; Rhynchospio; Scolelepis; Spio; Spiophanes) of spionid polychaetes were obtained; sequences of 27 of these species matched between adults and larvae. Morphology of the larvae was generally species‐specific, and larvae from the same genus mostly shared morphological features, with some exceptions. Color and number of eyes, overall body shape, and type and arrangement of pigmentation are the most obvious differences between genera or species. The morphological information on spionid larvae provided in this study contributes to species or genus level larval identification of this taxon in the studied area. Identification keys to genera and species of planktonic spionid larvae in northeastern Japan are provided. The preliminary results of the molecular phylogeny of the family Spionidae using 18S and 16S rRNA gene regions are also provided.

A new spionid polychaete was discovered in deep-sea sediments in the eastern Mediterranean Sea during an expedition by the Ocean Exploration Trust. Specimens were collected by the E/V Nautilus in August 2012 off Turkey, at a depth of 2216 m on the Anaximander Seamount at the Amsterdam mud volcano site. Cores were taken from sediments covered with microbial mats. The new species belongs to the Pygospiopsis-Atherospio Group, which has unusual neuropodial hooks, modified neurosetae in some anterior setigers, and branchiae in middle body segments that are broad, flattened, and fused to the dorsal lamellae. The new species is assigned to a new genus and species, Aciculaspio anaximanderi n. gen., n. sp., and is unusual in having a reduced setiger 1 lacking notosetae; well-developed pre- and postsetal lamellae that encompass the neurosetae and notosetae; notopodial lamellae free from the branchiae in anterior setigers that become fused and flattened in middle and posterior segments; unidentate hooded hooks in both noto- and neuropodia; neuropodial spines in setigers 4–10; and a pygidium with three anal cirri. Aciculaspio anaximanderi n. gen., n. sp. is the first species in the Atherospio-Pygospiopsis Group collected from a deep-water cold seep habitat.

Microspio moorei (Gravier, 1911) Figures 2A–G; 3A–K Mesospio moorei Gravier, 1911a: 100–105, Plates VII, figs 80–83, VIII, 84–86.— Gravier, 1911b: 313.— Augener, 1932: 39–40.— Hartman, 1966: 17, Plate IV, figs 1–3.— Bellan, 1975: 789.— Blake, 1983: 241.— Sicinski et al. 2011: 35, Table 1: 37. Microspio moorei Foster, 1971: 35.— Maciolek, 1990: 1113–1115, Table 1. Microspio cf. moorei Petti et al. 2006: 166, Table 1.— Sicinski et al. 2011: 37. Microspio sp. Barbosa et al. 2010: 1158, Table 1. Material examined. All samples collected in Fildes Bay, King George Island, South Shetland Islands, Antarctic Peninsula; 62º12’31,32”S 58º57’45,86”W: UDEA: CEMUA: ANNE:001594 (8 specimens); 0.3 m depth, low tide. Coll. M. Londoño & I. Fonseca. Feb. 24, 2017. UDEA: CEMUA: ANNE:001595 (7); 0.3 m depth, low tide. Coll. M. Londoño & I. Fonseca. Feb. 24, 2017. UDEA: CEMUA: ANNE:001596 (2); 1.3 m depth low tide. Coll. M. Londoño & I. Fonseca. Feb. 26, 2017. UDEA: CEMUA: ANNE:001597 (9); 1.3 m depth low tide. Coll. M. Londoño & I. Fonseca. Feb. 24, 2017. UDEA: CEMUA: ANNE:001598 (3); 1.3 m depth low tide. Coll. M. Londoño & I. Fonseca. Feb. 24, 2017. Description. Complete specimens with 4.1–12.3 mm long and 0.5–1.5 mm wide with 36–62 segments. In life and in alcohol, prostomium, peristomium, caruncle, and dorsum of first five chaetigers dark, subsequent segments with diminishing pigmentation, palps dark (Fig. 2A, B), ventral surface of first five segments with dark pigmentation, subsequent segments with pigmentation decreasing gradually, concentrated along midline up to chaetiger 12 (Fig. 2C); in life, specimens pink with visible blood vessel running inside the branchiae (Fig. 2D); ventral epidermal glands absent. Prostomium broadly rounded and tapered anteriorly (Figs 2A, 3A), posteriorly narrow, tapered in a narrow caruncle reaching the base of chaetiger 2 (Fig. 3A), with slightly elevated keel near base of palps (Fig. 3A). Occipital tentacle absent. Two pairs of black eyespots arranged in trapezoid, anterior pair larger, crescent-shaped, widely spaced; posterior pair smaller, rounded, closely spaced (Figs 2A, B, D, 3A). Peristomium long, collar-like, partially enveloping prostomium and extending around base of palps, not forming lateral wings (Figs 2A, 3A, B), separated from chaetiger 1. Palps long, thick, extending to chaetigers 8–11; palps longitudinally grooved, with dark brown pigment along both sides, except basally (Figs 2B, D, E, 3B); palpal sheath short, smooth, fused to anterior base of palps (Fig. 2B, D). Nuchal organs with medial ciliary bands around caruncle, extending to chaetiger 2, then turning laterally, with small gap between this and the second lateral band. From chaetiger 3, dorsum with two transverse rows of ciliated patches; the first row extending between branchial bases; the second row widely separated from the first, near segmental groove (Figs 2A, 3A), transverse rows of ciliated patches visible (Fig. 2A) up to around chaetiger 22. Branchiae from chaetiger 2 to almost posterior end; the first pair of branchiae slightly shorter and thinner or as long as those on following chaetigers (Figs 2A, D, 3A, C); longest through mid-body region, reaching dorsal midline (Fig. 2A, E), then becoming very small; short posteriorly (Fig. 2F); branchiae partly fused at the base with notopodial postchaetal lamellae anteriorly (Figs 2A, B, 3A), increasingly separate from lamellae posteriorly, flattened, robust, elongate, distally rounded (Figs 2A, B, 3A), with long cilia on inner margin. Notopodial postchaetal lamellae triangular, short on chaetiger 1; lamellae on chaetigers 2–8 small, subtriangular with rounded ventral edge (Figs 2A, E, 3A, C); thereafter becoming oval and slightly decreasing in size throughout the body (Fig. 2F). Notopodial prechaetal lamellae very short, rounded on chaetiger 1, robust, subtriangular on chaetigers 2–9 (Figs 2A, B, 3A, C); subsequent lamellae progressively decreasing in size, becoming round and smaller (Fig. 2F). Neuropodial postchaetal lamellae small, triangular on chaetiger 1 (Fig. 2E); subtriangular on chaetiger 2 (Figs 2E, 3B); subsequent neuropodial lamellae large, rounded, wider (Figs 2E, 3C), up to end of the body (Fig. 2F). Neuropodial prechaetal lamellae absent. Notopodial capillary chaetae on chaetiger 1 longer, thinner and alimbate, arranged in one row; capillary chaetae from chaetiger 2 arranged in two rows; both rows with slightly granulated, striated, unilimbate chaetae (Fig. 3D); posterior row with very long and pointed chaetae. All chaetigers with an additional superior fascicle; anterior chaetigers with 4–7 long, granulated capillary chaetae (Fig. 3E); middle chaetigers with short, thin, smooth and alimbate chaetae; posterior chaetigers with slender, smooth, long and alimbate chaetae (Fig. 3K). Neuropodial capillaries of chaetigers 1–3 arranged in one row; capillaries long, smooth, unilimbate; capillaries of subsequent chaetigers arranged in two rows, capillaries of both rows of same length, most dorsal capillaries stout, slightly granulated, striated and unilimbate (Fig. 3F); capillaries of ventral region slender, slightly granulated, unilimbate (Fig. 3G); inferior fascicle with 4–6 long, smooth, thin capillaries (Fig. 3H) in position of sabre chaetae usually present in most anterior chaetigers, around chaetiger 13 with granulate and long sabre chaetae (Fig. 3I), up to 3 per fascicle. Neuropodial hooded hooks (Fig. 3J) from chaetigers 14–17; up to 11 hooks per fascicle, accompanied by granulated, unilimbate capillaries in first chaetiger with hooks, thereafter only hooks. All hooks bidentate, with small tooth above main tooth (Fig. 3J). Pygidium long, with four short highly glandular digitate lobes surrounding the anal opening (Fig. 3K). Methyl Green staining pattern. Body destains fairly rapidly; stain is retained briefly on anterior-most end of body. Anterior parapodial lamellae initially stain deeply but rapidly lose the stain. Variation. The segments where the hooded hooks started varied from segment 14 in small specimens to segment 17 in the longest specimens. A significant positive linear regression was found between the chaetiger where the hooded hooks first appeared and the body length (R 2 = 0.22474; Permutation p = 0.0031) (Fig. 4A). Specimens with an average length of 6.3 mm (SD±0.94) showed hooks starting on chaetiger 14, and as the body length increased, hooks first appeared on segments up to chaetiger 17 in individuals with a length close to 11 mm (SD±1.17). Even though the statistical analysis was not significant (R 2 = 0.10305; Permutation p = 0.0653), it was also observed that in individuals with greater body width, hooded hooks first appeared on posterior segments, in such a way that specimens with a diameter greater than 1.1 mm (SD±0.30) had hooks starting in chaetiger 17 (Fig. 4B). A multivariate regression analysis supports these results and shows that as the polychaetes grow in length and width, the chaetiger where the hooded hooks first appear is progressively later (R 2 = 0.2235; p(regr) = 0.01907). Discussion. Specimens herein described become the only additional material that has been used for taxonomic purpose, since none of the recent material used for ecological studies from the type locality, Admiralty Bay, and identified as Microspio moorei (Sicinski 2004; Pabis & Sicinski 2010a, b), Microspio cf. moorei (Petti et al. 2006), Microspio sp. (Barbosa et al. 2010), and Mesospio moorei (Sicinski et al. 2011), was available for checking their identity. Taxonomic information given by Hartman (1966) and Blake (1983) are based on the description by Gravier (1911a), and comparative notes by Maciolek & Blake (2021) are based on the description by Blake (1983). The quantity of individuals obtained from Fildes Bay, adjacent to the type locality, were sufficient to evaluate the relationship between the segment where different types of chaetae first appear and the body length and number of segments presented by each complete individual. The original description, based on the holotype with 16 mm in length, considered chaetiger 15, where hooded hooks appear for the first time, as a character with taxonomic importance (Gravier, 1911a); nevertheless, regression analyses from additional material herein studied indicate that this character is size dependent, so increasing body length leads to hooded hooks occurring more posteriorly on the body (Fig. 4). More analyses on ontogenetic development are needed to assess the physiological bases of this morphological variability in chaetation. Type locality: Admiralty Bay, King George Island, South Shetland Islands, Antarctic Peninsula. Distribution: This species has been identified only in the South Shetland Islands, Antarctic Peninsula, in Admiralty Bay by Gravier (1911a, b), Sicinski (2004), Pabis & Sicinski (2010a, 2010b), and in its different inlets (lagoons or fjord-like shaped bays), Mackellar, Martel, and Ezcurra (Barbosa et al. 2010), in Deception Island by Augener (1932), and in Fildes Bay, King George Island, in this study. From 0.3 m (this research) to 30 m depth (sensu Augener 1932)., Published as part of Fonseca-González, Idalyd, Londoño-Mesa, Mario H. & Delgado-Blas, Víctor H., 2022, Redescription of Microspio moorei (Gravier, 1911) (Annelida: Spionidae) with inclusion of a taxonomic key for all the species of the genus, pp. 334-344 in Zootaxa 5120 (3) on pages 337-341, DOI: 10.11646/zootaxa.5120.3.2, http://zenodo.org/record/6389455, {"references":["Gravier, C. (1911 a) Annelides polychetes recueillis par la seconde expedition antarctique francaise (1908 - 1910). Deuxieme Expedition Antarctique Francaise (1908 - 1910) Comamandee par le Dr. Jean Charcot, 1, 1 - 165, 12 plates.","Gravier, C. (1911 b) Expedition Antarctique Francaise du \" Pourquoi-Pas \", dirigee par le Dr. J. - B. Charcot (1908 - 1910). Especes nouvelles d'annelides polychetes. Bulletin du Museum National d'Histoire Naturelle, 17 (5), 310 - 316.","Augener, H. (1932) Antarktische und antiboreale Polychaeten nebst einer Hirudinee. Scientific Results of the Norwegian Antarctic Expeditions 1927 - 1928 et sqq., instituted and financed by Consul Lars Christensen. Det norske videnskaps-akademi i Oslo, 9, 1 - 85. https: // doi. org / 10.2307 / 4080428","Hartman, O. (1966) Polychaeta Myzostomidae and Sedentaria of Antarctica. In: Antarctic Research Series. Vol. 7. American Geophysical Union, Washington, D. C., pp. 1 - 158, 46 plates., 5 charts. https: // doi. org / 10.1029 / AR 007","Blake, J. A. (1983) Polychaetes of the family Spionidae from South America, Antarctica and adjacent seas and islands. In: Kornicker, L. (Ed.), Biology of The Antarctic Seas. Vol. 14. Antarctic Research Series 39. American Geophysical Union, Washington, D. C., pp. 205 - 287. https: // doi. org / 10.1029 / AR 039 p 0205","Sicinski, J., Jazdzewski, K., De Broyer, C., Presler, P., Ligowski, R., Nonato, E. F., Corbisier, T. N., Petti, M. A. V., Brito, T. A. S., Lavrado, H. P., Blazewicz-Paszkowycz, M., Pabis, K., Jazdzewska, A. & Campos, L. S. (2011) Admiralty Bay Benthos Diversity - A census of a complex polar ecosystem. Deep Sea Research II, 58, 30 - 48. https: // doi. org / 10.1016 / j. dsr 2.2010.09.005","Foster, N. M. (1971) Spionidae (Polychaeta) of the Gulf of Mexico and the Caribbean Sea. Studies on the Fauna of Curacao and other Caribbean Islands, 36, 1 - 183.","Maciolek, N. J. (1990) A redescription of some species belonging to the genera Spio and Microspio (Polychaeta: Annelida) and description of three new species from the northwestern Atlantic Ocean. Journal of Natural History, 24, 1109 - 1141. https: // doi. org / 10.1080 / 00222939000770701","Petti, M. A. V., Nonato, E. F., Skowronski, R. S. P. & Corbisier, T. N. (2006) Bathymetric distribution of the meiofaunal polychaetes in the nearshore zone of Martel Inlet, King George Island, Antarctica. Antarctic Science, 18, 163 - 170. https: // doi. org / 10.1017 / S 0954102006000186","Barbosa, L. S., Soares-Gomes, A. & Paiva, P. C. (2010) Distribution of polychaetes in the shallow, sublittoral zone of Admiralty Bay, King George Island, Antarctica in the early and late austral summer. Natural Science, 2 (10), 1155 - 1163. https: // doi. org / 10.4236 / ns. 2010.210143","Sicinski, J. (2004) Polychaetes of Antarctic sublittoral in the proglacial zone (King George Island, South Shetland Islands). Polish Polar Research, 25 (1), 67 - 96.","Pabis, K. & Sicinski, J. (2010 a). Polychaete fauna associated with holdfasts of the large brown alga Himantothallus grandifolius in Admiralty Bay, King George Island, Antarctic. Polar Biology, 33, 1277 - 1288. https: // doi. org / 10.1007 / s 00300 - 010 - 0816 - x","Maciolek, N. J. & Blake, J. A. (2021) New species of Microspio Mesnil, 1896 (Annelida: Spionidae), with additions to the description of M. pigmentata (Reish, 1959) and comparative notes on all members of the genus. Proceedings of the Biological Society of Washington, 134 (1), 265 - 293. https: // doi. org / 10.2988 / 0006 - 324 X- 134.1.265","Pabis, K. & Sicinski, J. (2010 b). Distribution and diversity of polychaetes collected by trawling in Admiralty Bay: An Antarctic glacial fiord. Polar Biology, 33 (2), 141 - 151. https: // doi. org / 10.1007 / s 00300 - 009 - 0692 - 4"]}

Microspio moorei (Gravier, 1911), described from Admiralty Bay, King George Island (Antarctic Peninsula), has not been recorded since the original description, based on a single specimen, the holotype. Thus, subsequent comments and observations about the species have been made based only on the original description and with no information on morphological variations of the species. A re-description of this species is presented based on new material collected from a bay near the type locality, with detailed descriptions and illustrations of morphological characters. A key to all species of Microspio Mesnil, 1896 is provided. This research was part of the Colombian Antarctic Program, in collaboration with the Chilean Antarctic Institute (INACH).

Subgenus Parascolelepis Maciolek, 1987 Diagnosis of the genus. Prostomium pointed anteriorly, extending posteriorly into caruncle; occipital antennae present or absent. Peristomium well-developed, with or without lateral wings. Palps without ciliated groove, but with transverse ciliary bands; basal sheaths usually well-developed, with or without papillae. Branchiae from chaetiger 2; anterior branchiae complete or partially fused to notopodial lamellae. Hooks in neuropodia present; multidentate with several apical teeth above main fang, with strongly curved shaft. Hooks in notopodia absent. Pygidium with oval disc or multilobed., Published as part of Lee, Geon Hyeok & Min, Gi-Sik, 2022, Two new Scolelepis species (Annelida: Spionidae) from the Yellow Sea in Korea, pp. 221-237 in Zootaxa 5092 (2) on page 222, DOI: 10.11646/zootaxa.5092.2.5, http://zenodo.org/record/5876652, {"references":["Maciolek, N. J. (1987) New species and records of Scolelepis (Polychaeta: Spionidae) from the East coast of North America, with a review of the subgenera. Bulletin of the Biological Society of Washington, 7, 16 - 40."]}

Scolelepis (Parascolelepis) anterobranchiata sp. nov. Figures 2���5 Material examined. Holotype. complete specimen (NIBRIV0000890299), without palps (Fig. 2A), formalin, Yellow Sea, Korea, 34��55'12.0"N, 126��03'26.2"E, 4 Oct 2020, intertidal muddy sand, coll. Lee GH. Paratypes. Seven complete (NIBRIV0000890300���6) and one af (VSJAIV0000001433), formalin, collection details same as holotype, coll. Lee GH. Additional material. 4 complete (NIBRIV0000890307���9 for molecular analysis), same data as holotype, 95% ethanol; 2 af, formalin, same locality as holotype, 5 Oct 2020, coll. Lee GH. Diagnosis. Prostomium elongated, anterior conical with broadly rounded point, posteriorly extended into low caruncle attached to dorsum; caruncle extending to end of chaetiger 2 with slight elevation on posterior part. Palps long, thin, with smooth sheath at base, usually distinctly thickened at base part with globular expansions; palps with separated, single row of mucus-secreting cells and accompanying cilia; irregular longitudinal swellings present but not parallel. Chaetiger 1 well developed, with rounded lamellae in both rami; notochaetae absent. Branchiae from chaetiger 2 to chaetigers 18���19. Notopodial postchaetal lamellae foliate with pointed tip, largest on chaetigers 5���12; almost entirely fused but distally free from branchiae; from chaetiger 15 to middle chaetigers notopodia becoming smaller. Neuropodial postchaetal lamellae broadly rounded, from chaetiger 16 slightly notched. Neuropodial hooded hooks from chaetigers 18���19 with 2 pairs of teeth in parallel position surmounting well-developed main fang, apical pair smallest. Pygidium slightly broad, rounded, with anus opening dorsally. Description. Holotype complete with 58 chaetigers, about 0.9 mm wide and about 7.0 mm long (Fig. 2A). Other specimens complete with 56���63 chaetigers, similar to holotype in width and length. Body dorsoventrally flattened anteriorly, cylindrical posteriorly (Fig. 2A, B). Prostomium elongated, anterior conical with broadly rounded point, posteriorly extended into low caruncle attached to dorsum; caruncle extending to end of chaetiger 2 with slight elevation on posterior part; two pairs of reddish eyes (in both live and fixed specimens) arranged in trapezoid, anterolateral pair slightly larger, crescent-shaped, widely separated, and posterior pair smaller, rounded; occipital antenna absent (Fig. 3A, B). Peristomium well-developed, separated from prostomium without furrows, not forming lateral wings (Fig. 3B). Palps long, thin, reaching about two-thirds of body in live specimens (Fig. 2B) (but rather thickened in formalin and ethanol-fixed specimens (Fig. 2C), reaching to chaetigers 15���22), with smooth sheath at base, usually distinctly thickened at basal part with globular expansions (weak expansions in two specimens) (Figs. 2C, 5A); palps with separated, single row of mucus-secreting cells and accompanying cilia (Fig. 5B, C); long rows approximately 72 ��m long, short rows approximately 10 ��m long; irregular longitudinal swellings present but not parallel, with smooth inner portion surrounded by mucus-secreting cells and cilia (Fig. 5B, C). Low but distinct transverse ciliated bands present throughout body. Chaetiger 1 well developed, with rounded lamellae in both rami; notochaetae absent (Fig. 3A, B). Branchiae from chaetiger 2 to chaetigers 18���19, longest on chaetigers 5���12, quickly decreasing in size posteriorly; branchiae long cirriform with pointed tips, longer than notopodial postchaetal lamellae until chaetiger 15; accessory branchiae absent (Fig. 4). Notopodial postchaetal lamellae foliate with pointed tips, largest on chaetigers 5���12; almost entirely fused but distally free from branchiae (Fig. 4B���D); from chaetiger 15 to middle chaetigers notopodia becoming smaller (Fig. 4E); notopodia of middle to posterior chaetigers becoming slightly larger with foliate but less folded notopodial postchaetal lamellae (Fig. 4F). Neuropodial postchaetal lamellae broadly rounded (Fig. 4A���D), from chaetiger 16 slightly notched (Fig. 4E), from chaetiger 23 divided into rounded lobe in interramal position and low flattened postchaetal lamella; interramal lobe becoming conical with rounded tip on posterior chaetigers (Fig. 4F). Anterior chaetae all non-granulated capillaries with narrow sheaths (Fig. 3D), arranged in two rows in both rami, anterior row slightly shorter than posterior row; from about chaetiger 18, 3���5 long, thin non-limbate notochaetae arranged in irregular rows, more posteriorly arranged in bundle (Fig. 4F). Neuropodial hooded hooks from chaetigers 18���19 (18 in holotype), numbering 7���8 per fascicle at first, then increasing to 15���16 per fascicle posteriorly; hooded hooks with strongly curved shaft, with open hoods (Figs. 2D, 3E, 5D); hooks with 2 pairs of teeth in parallel position surmounting well-developed main fang, apical pair smallest (Fig. 3E); hooks not accompanied by capillaries. Ventral sabre chaetae absent. Pygidium slightly broad, rounded, with anus opening dorsally (Figs. 3C, 5E). Pigmentation. Whitish color in live specimens with orange-brownish pigmentation on the prostomium, peristomium, and base of palps. In formalin- or ethanol-fixed specimens, orange-brownish pigmentation usually fades or is completely lost (pigmentation well-preserved in only two fixed specimens); if pigmentation is preserved, conspicuously present on the caruncle and basal sheaths of palps (Fig. 2C). Methyl green staining pattern. Stain retained on prostomium, posterior part of caruncle, peristomium, notopodial postchaetal lamellae, and distal tips of branchiae. Anterior and middle segments with horizontal bands of deeply staining cells on venter. Etymology. The Latin name of the new species refers to having branchiae only on the anterior body region. Habitat and distribution. The new species was found in the muddy sand of the intertidal zone of the Yellow Sea. Remarks. Scolelepis (Parascolelepis) anterobranchiata morphologically is most similar to S. (P.) globosa from China, in having the palps with smooth globular expansions at the base, absence of notochaetae on chaetiger 1, notopodial postchaetal lamellae partially fused with branchiae in anterior chaetigers, and neuropodial hooded hooks appearing tridentate in lateral view (Wu & Chen 1964, Blake et al. 2019). Based on the current knowledge, only these two species have palps with smooth globular expansions in this subgenus. However, the new species differs from S. (P.) globosa by the absence of an occipital antenna instead of presence, branchiae appearing in the anterior part of the body instead of the whole body, and neuropodial hooded hooks from chaetigers 18���19 instead of 21 (Wu & Chen 1964). The new species is also similar to S. (P.) geniculata from Japan in the absence of an occipital antenna and flattened postchaetal neuropodial lamellae but differs in the absence of papillae on palps instead of presence, the absence of notochaetae on first chaetigers instead of presence, notopodial postchaetal lamellae partially fused to branchiae in the anterior part of the body instead of completely fused, and two pairs of apical teeth instead of three pairs (Imajima 1992). The palp ciliation patterns are of important taxonomic character (Williams 2007). The palps of the new species have a single row of mucus-secreting cells and accompanying cilia with irregular longitudinal swellings. This is the first palp ciliation pattern described in detail for the subgenus Parascolelepis and it is unique among the species of Scolelepis studied to date., Published as part of Lee, Geon Hyeok & Min, Gi-Sik, 2022, Two new Scolelepis species (Annelida: Spionidae) from the Yellow Sea in Korea, pp. 221-237 in Zootaxa 5092 (2) on pages 224-228, DOI: 10.11646/zootaxa.5092.2.5, http://zenodo.org/record/5876652, {"references":["Wu, B. L. & Chen, M. (1964) A new species of polychaete worm of the Family Spionidae from Chushan Archipelago, East China Sea. Acta Zootaxonomica Sinica, 1, 195 - 198.","Blake, J. A., Maciolek, N. J. & Meissner, K. (2019) Spionidae Grube, 1850. In: Purschke G., Schmidt-Rhaesa A., Boggemann M. & Westheide W. (Eds.), Annelida. Vol. 2. Pleistoannelida, Sedentaria II. De Gruyter, Berlin, pp. 1 - 102. https: // doi. org / 10.1515 / 9783110291681","Imajima, M. (1992) Spionidae (Annelida, Polychaeta) from Japan VIII. The genus Scolelepis. Bulletin of the National Science Museum, Tokyo, Series A (Zoology), 18, 1 - 34.","Williams, J. D. (2007) New records and description of four new species of spionids (Annelida: Polychaeta: Spionidae) from the Philippines: the genera Dispio, Malacoceros, Polydora, and Scolelepis, with notes on palp ciliation patterns of the genus Scolelepis. Zootaxa, 1459 (1), 1 - 35. https: // doi. org / 10.11646 / zootaxa. 1459.1.1"]}

Subgenus Scolelepis Blainville, 1828 Diagnosis of the genus. Prostomium pointed anteriorly, trifid (sagittiform), sometimes truncate, extending posteriorly into caruncle; occipital antennae present or absent. Peristomium well-developed, with or without lateral wings. Palps without ciliated groove, but usually with transverse ciliary bands; basal sheaths weakly developed. Branchiae from chaetiger 2; anterior branchiae complete or partially fused to notopodial lamellae. Hooded hooks in neuropodia present, 0���3 apical teeth above main fang, with straight or falcate shaft; hooks in notopodia present or absent. Pygidium with oval disc or multilobed., Published as part of Lee, Geon Hyeok & Min, Gi-Sik, 2022, Two new Scolelepis species (Annelida: Spionidae) from the Yellow Sea in Korea, pp. 221-237 in Zootaxa 5092 (2) on page 228, DOI: 10.11646/zootaxa.5092.2.5, http://zenodo.org/record/5876652, {"references":["Blainville, H. de. (1828) Dictionnaire des Sciences Naturelles. F. G. Levrault, Strasbourg, 47, 368 - 501."]}