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Glandiceps talaboti (Marion, 1876) (Fig. 7): a deep-sea worm with affinities to echinoderms and chordates (Hemichordata, Enteropneusta, Spengelidae) In July–October of 1875, Antoine-Fortuné Marion had undertaken a dredging inventory of the deep-sea bottom to the south-east of the Bay of Marseille, to complete his previous studies of the littoral zone (Marion 1873). These dredging efforts were realized thanks to the financial support of a group of his friends (Talabot, Benet, Renouard, Meilhac, Mazel, Gallas and Martin). Among the most interesting discoveries he made was a new enteropneust species from yellowish sticky mud at 350 m depth in the area then called “Plateau Marsilli”. First Enteropneusta from Provence at this time, it was shortly described by Marion in 1876 as Balanoglossus talaboti, to honour one of his friends and sponsors. Later, he gave a very complete description of the species, pink-coloured, cylindrical and composed of a short anterior and conical proboscis, a collar where the mouth opens, and a trunk (Marion, 1885, 1886). Marion could observe the animal alive, crawling on the sediment surface of an aquarium for several weeks and noticed the emission of thick mucus with iodine smell when the animal was disturbed. Later, Spengel (1893) studied the enteropneusts of the Bay of Naples and subdivided the genus Balanoglossus in four genera, assigning Marion’s species to the genus Glandiceps, even becoming its type-species. The Enteropneusta, although not speciesrich, are part of the Hemichordata and as such have a major evolutionary interest due to their close relationships with both Echinodermata and Chordata. Glandiceps talaboti is a Mediterranean endemic species. It was later collected in bathyal mud of the Cassidaigne and Lacaze-Duthiers canyons (DPR096 cruise, see photo, Zibrowius personal communication), possibly along Egyptian coasts near Alexandria, and also recently off Turkey (Çevik & Erguden 2005)., Published as part of 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, pp. 213-252 in Zootaxa 5249 (2) on page 235, DOI: 10.11646/zootaxa.5249.2.3, http://zenodo.org/record/7687250, {"references":["Marion, A. F. (1876) Dragages profonds au large de Marseille (Juillet-Octobre 1875). Note preliminaire. Revue des Sciences Naturelles, 4 (4), 469 - 477.","Marion, A. F. (1873) Recherches sur les animaux inferieurs du golfe de Marseille. Annales des Sciences Naturelles, 5 (17), 1 - 23.","Marion, A. F. (1885) Sur deux especes de Balanoglossus. Comptes Rendus de l'Institut, 101, 1289 - 1291.","Marion, A. F. (1886) Etudes zoologiques sur deux especes d'Enteropneustes (Balanoglossus hacksi & Balanoglossus talaboti). Archives de Zoologie Experimentale & Generale, 4, 305 - 326.","Spengel, J. W. (1893) Die Enteropneusten des Golfes von Neapel. In: Fauna und Flora des Golfes von Neapel und der angrenzenden Meeres-Abschnitte. Herausgegeben von der Zoologischen Station zu Neapel, Berlin, 756 pp. https: // doi. org / 10.5962 / bhl. title. 11517","Cevik, C. & Erguden, D. (2005) First record for two species [Balanoglossus clavigerus delle Chiaje, 1829, Glandiceps talaboti (Marion, 1876)] of the Phylum Hemichordata on the coast of Turkey. Turkish Journal of Zoology, 29, 141 - 145."]}

Paracheilinus hemitaeniatus Randall & Harmelin-Vivien, 1977 (Fig. 10): the half-banded flasherwrasse of mesophotic habitats off Madagascar Paracheilinus hemitaeniatus is a rare brightly colored fish species sampled for the first time in 1972, at 45 m depth on the outer slope of the barrier-reef off Toliara, SW Madagascar. Created in 1961 as a branch of the SME, the marine station of Toliara (Tuléar) hosted many scientists who studied the coral reef communities and described a number of new species of marine organisms, contributing largely to improve our knowledge on coral reef diversity. The half-banded flasherwrasse is known only from the south-west of the Indian Ocean, Madagascar and Comoro Islands, where this elusive and beautiful species remains a ‘holy grail’ for photographers. It belongs to the Labridae, a highly diversified fish family, where sexual dimorphism is so pronounced that males, females and juveniles have often been described as separate species by early ichthyologists! Such color dimorphism is viewed as an adaptation to sexual selection and life in coral reefs, where it is more conspicuous than in other environments. Labrids play an important role in the trophic functioning of coral reefs due to their high abundance and diverse feeding behaviors, from small zooplanktivores, crustacean and mollusk feeders to large-sized piscivores. P. hemitaeniatus is a small (, Published as part of 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, pp. 213-252 in Zootaxa 5249 (2) on page 238, DOI: 10.11646/zootaxa.5249.2.3, http://zenodo.org/record/7687250, {"references":["Randall, J. E. & Harmelin-Vivien, M. (1977) A review of the labrid fishes of the genus Paracheilinus with description of two new species from the Western Indian Ocean. Bulletin du Museum National d'Histoire Naturelle, Paris, 436 (Zoologie, 306), 329 - 342."]}

Hemimysis speluncola Ledoyer, 1963 (Fig. 8): an unexpected model for Mediterranean climate change and evolutionary ecology Being among the first SME researchers to use SCUBA, in 1958 Laborel &Vacelet (1958) reported of surprisingly dense swarms of a small red mysid (Crustacea: Mysida) in the darkest reaches of a small underwater marine cave of the Bay of Marseille at Niolon. Closely resembling the well-known Atlantic species Hemimysis lamornae (Couch 1856), it was later recognized that such swarms were common in dark caves of the Marseille area, and that some of them were made of a new species, Hemimysis speluncola Ledoyer, 1963. For twenty years (1966–1986), the new species then became a model for behavioural ecology and ecophysiology, as it was found relatively easy to maintain in aquarium (e.g. Macquart-Moulin & Patriti 1966; Gaudy et al. 1980; Bourdillon & Castelbon 1983; Passelaigue & Bourdillon 1986). Among other things, H. speluncola displayed original horizontal circadian migrations in and out of caves to feed, in a way similar to the vertical migrations of deep-sea zooplankton. Suddenly, in the late 1990s, concomitant with the first marine heat wave and invertebrate mass mortalities recorded in the NW Mediterranean, Chevaldonné & Lejeusne (2003) provided evidence that, in most of its known geographic range, H. speluncola had vanished, gradually being replaced by the more thermophilic Hemimysis margalefi Alcaraz, Riera & Gili, 1986. This was the first documented Mediterranean warming-induced species shift and it triggered a series of studies on the Hemimysis species (many of which cryptic) present in the Atlantic-Mediterranean area, to investigate their molecular phylogeography and evolutionary history. Today, cave-dwelling Hemimysis, including the nowendangered H. speluncola, have become a model to study the effect of natural habitat fragmentation on population connectivity (Lejeusne & Chevaldonné 2006; Rastorgueff et al. 2014)., Published as part of 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, pp. 213-252 in Zootaxa 5249 (2) on page 235, DOI: 10.11646/zootaxa.5249.2.3, http://zenodo.org/record/7687250, {"references":["Ledoyer, M. (1963) Hemimysis speluncola n. sp. Mysidace nouvelle des grottes sous-marines obscures. Recueil des Travaux de la Station Marine d´Endoume, 30 (45), 77 - 81.","Laborel, J. & Vacelet, J. (1958) Etude des peuplements d'une grotte sous-marine du golfe de Marseille. Bulletin de l'Institut Oceanographique, 1120, 1 - 20.","Macquart-Moulin, C. & Patriti, G. (1966) Remarque sur la biologie d' Hemimysis speluncola, Ledoyer, mysidace sciaphile des grottes sous-marines obscures de la region de Marseille. Recueil des Travaux de la Station Marine d'Endoume, 56, 253 - 258.","Gaudy, R., Guerin, J. P. & Pagano, M. (1980) Ecophysiologie comparee des mysidaces Hemimysis speluncola Ledoyer (cavernicole) et Leptomysis lingvura G. O. Sars (non cavernicole). Respiration et excretion. Journal of Experimental Marine Biology and Ecology, 44, 29 - 46. https: // doi. org / 10.1016 / 0022 - 0981 (80) 90099 - 4","Bourdillon, A. & Castelbon, C. (1983) Influence des variations de temperature sur la geotaxie de deux especes de mysidaces. Journal of Experimental Marine Biology and Ecology, 71, 105 - 117. https: // doi. org / 10.1016 / 0022 - 0981 (93) 90067 - X","Passelaigue, F. & Bourdillon, A. (1986) Distribution and circadian migrations of the cavernicolous mysid Hemimysis speluncola Ledoyer. Stygologia, 2, 112 - 118.","Chevaldonne, P. & Lejeusne, C. (2003) Regional warming-induced species shift in north-west Mediterranean marine caves. Ecology Letters 6 (4), 371 - 379. https: // doi. org / 10.1046 / j. 1461 - 0248.2003.00439. x","Alcaraz, M., Riera, T. & Gili, J. M. (1986) Hemimysis margalefi sp. nov. (Mysidacea) from a submarine cave of Mallorca Island, western Mediterranean. Crustaceana, 50, 199 - 203. https: // doi. org / 10.1163 / 156854086 X 00214","Lejeusne, C. & Chevaldonne, P. (2006) Brooding crustaceans in a highly fragmented habitat: the genetic structure of Mediterranean marine cave-dwelling mysid populations. Molecular Ecology, 15, 4123 - 4140. https: // doi. org / 10.1111 / j. 1365 - 294 X. 2006.03101. x","Rastorgueff, P. - A., Chevaldonne, P., Arslan, D., Verna, C. & Lejeusne, C. (2014) Cryptic habitats and cryptic diversity: unexpected patterns of connectivity and phylogeographical breaks in a Mediterranean endemic marine cave mysid. Molecular Ecology, 23 (11), 2825 - 2843. https: // doi. org / 10.1111 / mec. 12776"]}

Peyssonnelia rosa-marina Boudouresque & Denizot, 1973 (Fig. 9): an unsuspected Mediterranean rose garden It is perhaps one of the most abundant seaweeds in the Mediterranean Sea, since it thrives from the infralittoral to the widely extended and widespread coastal detritic bottoms, in the circalittoral, where it is often dominant. It is also a particularly elegant macrophyte, resembling a calcified rosebud, hence its name, Peyssonnelia rosa-marina. Like many red algae, this seaweed can live in rather low irradiance down to ca. 100 m depth; it is an important producer of carbonate sediment and is furthermore an ecosystem engineer that takes a significant part in the construction of the coralligenous beds so characteristic of the Mediterranean. Yet, it has long been confused with its sister species, Peyssonnelia polymorpha, until the 1970s. It was then very surprising to realize that such an abundant, conspicuous, and well-characterized species, both by its morphology and anatomy, had been overlooked for so long., Published as part of 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, pp. 213-252 in Zootaxa 5249 (2) on page 236, DOI: 10.11646/zootaxa.5249.2.3, http://zenodo.org/record/7687250, {"references":["Boudouresque, C. F. & Denizot, M. (1973) Recherches sur le genre Peyssonnelia (Rhodophycees). I. Peyssonnelia rosa-marina sp. nov. et Peyssonnelia bornetii sp. nov. Giornale Botanico Italiano, 107 (1), 17 - 27. https: // doi. org / 10.1016 / 0022 - 0981 (93) 90067 - X"]}

The Rhachotropis species (Fig. 12) of Mid-Atlantic Ridge deep-sea hydrothermal vents: R. flamina, R. licornia, R. pilosa Bellan-Santini, 2006 SME taxonomists also have taken part in the major adventure started with the 1977 discovery of deep-sea chemosynthetic animal communities. In the vicinity of hydrothermal vents of the Mid-Atlantic Ridge, 3 new species of Rhachotropis (Crustacea: Amphipoda: Eusiridae) were collected by sediment traps at 1700–2750 m depth: Rhachotropis flamina Bellan-Santini, 2006, Rhachotropis licornia Bellan-Santini, 2006, and Rhachotropis pilosa Bellan-Santini, 2006. With 63 species (Horton et al. 2021) this genus is found in all oceans with a large bathymetric distribution (0–7160 m) (L̂rz et al. 2018). It is the most common amphipod genus in bathyal and abyssal zones. Morphologically, Rhachotropis have a delicate body with slender pereiopods, long antennae and sometimes dorsal processes. However, some of them display antennae bearing complex and puzzling structures called calceoli (present in R. pilosa and R. licornia) that are believed to be part of sensory organs. Cuplike receptacles, arranged serially on the antennae, would act as non-visual sensory organs, ensuring the perception of sound and vibration stimuli by the amphipods. These likely mechanoreceptors are found in several amphipod species (Hurley 1980, Lincoln & Hurley 1981, Bellan-Santini 2015); some could be involved in the detection of mates, others to detect preys. However, at hydrothermal vents, they could also be a good way to locate active fluid emissions.

Schizoretepora hassi Harmelin, Bitar & Zibrowius, 2007 (Fig. 13): a mysterious bryozoan from the East Schizoretepora hassi is a cheilostomate bryozoan belonging to the Phidoloporidae, i.e. the family of the beautiful reteporid Reteporella grimaldii (Jullien, 1903), the so-called “lace coral” well-known of Mediterranean divers and which has been the first bryozoan in the world to be illustrated in the literature, by Rondelet in 1554. Among the bryozoans described from the material collected during surveys of the Station Marine d’Endoume, S. hassi is not the most spectacular and its features are only but typical of the family. It lives in shaded rocky habitats of the Lebanese littoral zone and has not yet been found anywhere else. What is surprising is that a Mediterranean species living in the shallow coastal zone with large, conspicuous colonies, had not been described before. The question of its status, steno-endemic of the Levantine Basin or Erythraean immigrant introduced in the Mediterranean, remains open. It was dedicated to Dr Hans Hass, Austrian biologist who was both a famous diving icon and a pioneer in scientific diving and underwater photography. In 1948, he also had written a thesis on the Mediterranean reteporids, collected by diving., Published as part of 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, pp. 213-252 in Zootaxa 5249 (2) on page 240, DOI: 10.11646/zootaxa.5249.2.3, http://zenodo.org/record/7687250, {"references":["Harmelin, J. - G., Bitar, G. & Zibrowius, H. (2007) Schizoretepora hassi sp. nov. (Bryozoa: Phidoloporidae) from Lebanon (Eastern Mediterranean) and reappraisal of Schizotheca serratimargo (Hincks, 1886). Cahiers de Biologie Marine, 48 (2), 179 - 186.","Jullien, J. & Calvet, L. (1903) Bryozoaires provenant des campagnes de l'Hirondelle (1886 - 1888). Resultats des campagnes scientifiques accomplies sur son yacht par Albert Ier, prince souverain de Monaco, 23, 1 - 188."]}

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

Genus Aspiculophora Ruiz et al. 2017 Diagnosis: Plakinidae without spicules, well-developed mesohyl with a collagen layer between ecto- and choanosome, with or without sub-ectosomal cavities. Leuconoid aquiferous system and aphodal choanocyte chambers. High abundance of prokaryotic symbionts.

Aspiculortis garifuna sp. nov. Etymology: The genus name Aspiculortis refers to the absence of skeleton and to the genetic proximity of Plakortis. The species name garifuna honors the ethnical and cultural diversity of the Garifuna people, descendants of the first Caribs, Arawak Amerindians and the African people who inhabited the Lesser Antilles. Diagnosis: Thick crust (about 5 mm thick) with irregular form. No spicules, nor fibrous skeleton. The surface is covered by ostia with a series of translucent canals ending in prominent oscula of about 2 mm diameter. One type of vacuolar cell abounds in the ectosome and is also present in the mesohyl. Examined material: Holotype: Muséum National d’Histoire Naturelle de Paris, France MNHN DJV202 Martinique, “Grotte Fer à Cheval” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark section of the cave, date 25/03/2012, sample code: 120325 MT4 b-TP6, collector: T. Pérez. Genbank accession number: MK 949483 Paratype: Muséum National d’Histoire Naturelle de Paris, France MNHN DJV203 Guadeloupe, “Grotte aux Barracudas” (16°27.301’ N, 61°32.253’ W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 30/05/2015, sample code: 150530GU5-CR6, collector: C. Ruiz. Genbank accession number: MK 949485 Other material examined: Bequia, The Grenadines “Full Moon Cave” (12°59.525’ N, 61°16.731’ W), 10-12 m depth, beneath an overhang, date 19/05/2015, sample code: 150519LG1-CR14, collector: C. Ruiz. Genbank accession number: MK 949484 Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark section of the cave, date 11/06/2011, sample code: 110613 MT4 -TP3, collector: T. Pérez. Genbank accession number: MK 949482 Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 11/06/2011, sample code: 110613 MT4 -TP8, collector: T. Pérez. Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 15/05/2015, sample code: 150515 MT4 -CR1, collector: C. Ruiz. Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 16/05/2015, sample code: 160515 MT4 -CR9, collector: C. Ruiz. Comparative material examined: Aspiculophora madinina Ruiz, Muricy, Lage, Domingos, Chenesseau & Pérez 2017, Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark section of the cave, date 16/05/2015, sample code: 160515 MT4 -CR10, collector: C. Ruiz. Plakina nathaliae (Ereskovsky et al. 2014), Saint Martin, “Basses Espagnoles” (18°07.821’N, 63°00.270’W), 15 m depth, beneath an overhang, date 27/05/2015, sample code: 270515SN5-TP01, collector: T. Pérez. Oscarella zoranja Pérez & Ruiz, 2018, Martinique, Rocher du Diamant, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark section of the cave, date 16/05/2015, sample code: 150516 MT4 -CR05, collector: C. Ruiz. Oscarella filipoi Pérez & Ruiz, 2018, Saint Lucie, “Anse Chastenet reef” (13°51.848’ N, 61°04.729’ W), 15 m depth, beneath an overhang, date 22/05/2015, sample code: 150522SL1-CR05, collector: C. Ruiz. Description: External morphology: Aspiculortis garifuna sp. nov. has an encrusting irregular form and a brown color in vivo and after fixation in ethanol. The largest specimen recorded measured 10 cm in diameter. This sponge is quite fragile. The smooth surface is pseudo-criblate, that it is to say covered by numerous ostia diverging soon under the epidermal surface in various inhalant canals. The sponge surface also presents a series of larger translucent exhalant canals ending in prominent oscula of about 2 mm in diameter. This dense network can appear contracted in some specimens (Figure 2 A-B). Internal Anatomy: No spicule nor fibrous skeleton. The ectosome is 40-60 µm thick (Figure 2 C-D). The aquiferous system is leuconoid. Inhalant canals are 10-15 µm wide, running perpendicular to the surface. Choanocyte chambers (15-33 µm in diameter) are diplodal, spherical to ovoid (Figure 2E). The proportion between mesohyl and choanocyte chambers is greater than 1. Cytology: Choanocytes are cylindrical, 5 µm wide and 7 µm high. Their nucleus is spherical (2 µm diameter) in apical position, their cytoplasm usually contains osmiophilic inclusions and vacuoles of about 2-3 µm in diameter that often harbor phagocytized bacteria (Figure 3A). The exo- and endopinacocytes are flagellated and flattened (12- 19 µm long; 3-4 µm wide) with several vacuoles and osmiophilic inclusions. The external surfaces of the exo- and endopinacocytes are covered with a double-layer of 0.5 µm thick glycocalyx (Figure 3B). One type of vacuolar cell is found in abundance in the ectosome, and to a lesser extent in the mesohyl. This irregular shaped-cell, 10 x 20 µm in dimension, harbors 2-4 translucent vacuoles which are 3 to 8 µm in diameter (Figure 3C) and which often contain dense or loose heterogeneous material (Figure 3D). No archaeocyte was observed. There is a high abundance of prokaryotic symbionts in the mesohyl, with at least five dominant morphotypes randomly distributed throughout the mesohyl (Figure 3E). The first morphotype is an ovoid cell 2 - 4 µm long, 2.5 – 3 µm wide with a clear cytoplasm. The second morphotype has the same ovoid shape and size but has a denser cytoplasm. The third morphotype is an irregular cell shape which is 2 – 4 µm long and about 1 – 2.5 µm wide. The fourth morphotype is bean-shaped, 2.5 - 3 µm long and about 0.5 wide. The fifth morphotype is circular with a diameter of about 0.5 µm. Ecology: This new sponge has been collected in the Caribbean islands (Lesser Antilles) of Guadeloupe, Martinique and Bequia. In all sites, this sponge inhabits vertical walls and ceilings of dark marine caves, located at depths between 10 and 25 m, in syntopy with several other Homoscleromorpha species. No sign of predation was observed. Serpulidae worms live in close association and are often observed living among the new sponge species (Figure 2B). Taxonomic remarks: Aspiculortis garifuna gen. nov. sp. nov. has an encrusting form, as do most of the cave-dwelling Homoscleromorpha. It clearly belongs to a well-supported clade gathering Plakortis species, but its pseudo-criblate surface is unique, and thus has never been observed in Plakortis. The lack of cytological description of Caribbean Plakortis did not allow any comparison with the cells content of the new sponge. The absence of skeleton and this original pseudo-criblate surface justify the creation of a new genus. The new sponge also clearly differs from the other skeleton-less Plakinidae by its external morphology and internal organization, particularly the proportion between mesohyl and choanocyte chambers and the low abundance of symbiotic microorganisms in the thinly encrusting Plakina nathaliae, and the thick collagen layer found in the ectosome of the massive Aspiculophora madinina, as well as its aphodal choanocyte chambers.

Oscarella minka sp. nov. Etymology: From the Quechuan mink’a (minga), this species name honors the pre-Columbian tradition of communal work for social purposes. Diagnosis: Thin crust less than 3 mm thick. Smooth surface. Ectosome 25 to 50 µm thick, well-developed mesohyl. Two types of vacuolar cells, leuconoid aquiferous system with diplodal choanocyte chambers. High abundance of prokaryotic symbionts in the mesohyl. Examined material: Holotype: Muséum National d’Histoire Naturelle de Paris, France MNHN DJV206 La Martinique, “Grotte Fer à Cheval” (14°27.882’ N, 61°01.162 W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 25/03/2012, sample code: 120325 MT4 b-TP8, collector: T. Pérez. Genbank accession number: MK 949481 Paratype: Muséum National d’Histoire Naturelle de Paris, France MNHN DJV207 Bequia, The Grenadines, “Full Moon Cave” (12°59.525’ N, 61°16.731’ W), 10-12 m depth, beneath an overhang, date 19/05/2015, sample code: 150519LG1-CR9, collector: C. Ruiz. Genbank accession number: MK 949480 Other material examined: Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 13/06/2011, sample code: 110613 MT4 -TP4, collector: T. Pérez. GenBank accession number: MK 949478 Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 15/05/2015, sample code: 150515 MT4 - CR2, collector: C. Ruiz. Genbank accession number: MK 949479 Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 13/06/2011, sample code: 110613 MT4 -TP6, collector: T. Pérez. Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 16/05/2015, sample code: 150516 MT4 -CR11, collector: C. Ruiz. Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 16/05/2015, sample code: 150516 MT4 -CR16, collector: C. Ruiz. Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 16/05/2015, sample code: 150516 MT4 -CR17, collector: C. Ruiz. Bequia, The Grenadines, “Full Moon Cave” (12°59.525’ N, 61°16.731’ W), 10-12 m depth, beneath an overhang, date 28/04/2015, sample code: 150428LG1-AE55, collector: A. Ereskovsky. Bequia, The Grenadines, “Full Moon Cave” (12°59.525’ N, 61°16.731’ W), 10-12 m depth, beneath an overhang, date 19/05/2015, sample code: 150519LG1-TP5, collector: T. Pérez. Guadeloupe, “Grotte Cathédrale” (16°27.740’ N, 61°31.837’ W), 18 m depth, on a vertical wall in the dark part of the cave, date 29/05/2015, sample code: 150529GU3-TP2, collector: T. Pérez. Guadeloupe, “Grotte aux Barracudas” (16°27.301’ N, 61°32.253’ W), 19 m depth, beneath an overhang, date 30/05/2015, sample code: 150530GU5-CR4, collector: C. Ruiz. Guadeloupe, “Grotte aux Barracudas” (16°27.301’ N, 61°32.253’ W), 19 m depth, beneath an overhang, date 30/05/2015, sample code: 150530GU5-CR10, collector: C. Ruiz. Comparative material examined: Oscarella filipoi, Martinique, Anse d’Arlet, Grande Anse, Pointe Burgos - Grotte Couleur (14°2.787’N, 61°5.351’W), 10 m depth, on a vertical wall in semi-dark conditions, date 11/06/2011, sample code: 110611 MT3 -TP05, collector: T. Pérez. Oscarella zoranja, “ Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, date 13/06/2011, sample code: 110613 MT4 -TP1, collector: T. Pérez

Genus Oscarella Vosmaer, 1884 Diagnosis: Homosclerophorida without skeleton, with a variable development of the ectosome with a collagen layer between ecto- and choanosome. The aquiferous system has a sylleibid-like or leuconoid organization, with spherical to ovoid eurypilous or diplodal choanocyte chambers arranged around large exhalants canals (Muricy & Díaz 2002). Mitochondrial genomes that have been sequenced so far encode a gene absent in other animal mitochondrial genomes: tatC (Ereskovsky et al. 2017).

Aspiculophora papillata sp. nov. Etymology: the species name refers to the papillate surface of this Plakinidae, papilla = nipple in Latin. Diagnosis: encrusting Aspiculophora with papillate surface. Collagen layer ( Examined material: Holotype: Muséum National d’Histoire Naturelle de Paris, France MNHN DJV204 Bequia, The Grenadines, “Full Moon Cave” (12°59.525’ N, 61°16.731’ W), 10-12 m depth, beneath an overhang, date 19/05/2015, sample code: 150519LG1-CR13, collector: C. Ruiz. Genbank accession number: MK 949486 Paratype: Muséum National d’Histoire Naturelle de Paris, France MNHN DJV205 Guadeloupe, “Grotte Cathédrale” (16°27.740’ N, 61°31.837’ W), 18 m depth, on a vertical wall in the dark part of the cave, date 29/05/2015, sample code: 150529GU3-CR1, collector: C. Ruiz. Other material examined: Martinique, “Grotte Zeb” (14°27.832’N, 61°01.065’W), 19 m depth, on a vertical wall in the semi-dark part of the cave, dates 15 and 16/05/2015, sample codes: 150515 MT4 -CR3, 150515 MT4 - CR6, 160515 MT4 -CR14, collector: C. Ruiz. Bequia, The Grenadines “Full Moon Cave” (12°59.525’ N, 61°16.731’ W), 10-12 m depth, beneath an overhang, date 19/05/2015, sample codes: 150519LG1-CR10, 150519LG1-CR13, 150519LG1-TP11, collectors: C. Ruiz & T. Pérez Comparative material examined: Aspiculophora madinina MNHN DJV 180, Rocher du Diamant “Grotte Zeb”, Martinique (14°26.5´N, 61°03.083´W), 12 m depth, date 13/06/2011, sample code: 110613 MT4 -TP11 collector: T. Pérez, Aspiculophora madinina, “ Grotte Amédien”, Guadeloupe (16°30.033’ N, 061°28.774’ W), 12 m depth, date 30/05/2015, sample code: 150530-GU6-TP07, collector: T. Pérez. Plakina nathaliae MNHN DJV 179, Rocher du Diamant “Grotte Zeb”, La Martinique (14°26.5´N, 61°03.083´W), 17 m depth, date 13/06/2011, sample code: 110613 MT4 -TP2, collector: T. Pérez. Description: External morphology: Aspiculophora papillata sp. nov. is a thinly encrusting irregular sponge which is quite hard to collect because of its fragile consistency. Collected specimens measured up to 10 cm wide and 1 mm thick. The sponge has a papillate surface and its color varies from yellow to light brown in vivo, whereas it is light brown in ethanol. Papillae are cylindrical, up to 3 mm high and about 1 mm in diameter. The top of the papillae is often larger with an umbrella-like form of 2-3 mm in diameter. Oscula of about 1 mm in diameter are sometimes visible in the top of the papillae (Figure 4A, B). Internal Anatomy: No spicule or fibrous skeleton. A collagen lager Cytology: Choanocytes are cylindrical, 5 µm wide and 8 µm high. Their nuclei are spherical, about 2 µm in diameter and are located in apical position. Their cytoplasm usually contains osmiophilic inclusions of about 0.1 µm in diameter in basal position (Figure 5A, B). Apopylar cells have a trapezoid shape (Figure 5A). Exo- and endopinacocytes are flat and flagellated (5-15 µm long; 1-2 µm wide) with a nucleus of about 2.5 µm in diameter (Figure 5C). One type of abundant vacuolar cell was found randomly distributed in the mesohyl. This cell has an ovoid to spherical shape, is 12-20 µm in diameter, and generally harbors one to five vacuoles occupying most of the volume of the cytoplasm. Some heterogeneous to filamentous materials can be seen inside the vacuoles, and microorganisms can be found in their cytoplasm (see arrow in Figure 5C). No archaeocyte was observed. The new species can be considered as an HMA sponge. At least four prokaryotic morphotypes seem to be dominant in the mesohyl (Figure 5D). The first morphotype is peanut-shaped, 2.5 µm long 0.5 µm wide, with a dense cytoplasm and a double membrane. The second morphotype is of similar size, is cylindrical in shape and has a translucent external membrane. The third morphotype has an irregular shape and is 2-4 µm long and 1 µm wide. The fourth morphotype is bean-shaped with a dense membrane and translucent cytoplasm. Ecology: The new sponge species was found in the Caribbean islands of Guadeloupe, Martinique and Bequia (Lesser Antilles). It lives in sympatry (and sometimes in syntopy) with A. madinina, on walls and ceilings of dark marine caves, where it is always found between 10 and 20 m depth. No sign of predation was observed, but the new species usually lives in close association with other sponges and invertebrates such as Serpulidae and Sabellidae worms (Figure 4A). Taxonomic remarks: Aspiculophora papillata sp. nov. is a skeleton-less Plakinidae like A. madinina. The new species mainly differs by its external morphology, the papillate surface being a trait observed for the first time among Homoscleromorpha. In contrast with A madinina, no dark exudate was recorded in contact with alcohol for A. papillata. The collagen layer between the exopinacoderm and the ectosome region in A. papillata sp. nov. is very thin in comparison with A. madinina. Another difference between these species is the presence of sub-ectosomal cavities in A. papillata sp. nov. that do not exist in A. madinina. Both species share the leuconoid aquiferous system with aphodal choanocyte chambers, only one type of vacuolar cell which is mostly concentrated in the ectosome and similar microbial compositions.

Aspiculortis gen. nov. Diagnosis: Plakinidae without spicules. Smooth pseudo-criblate surface covered by numerous ostia diverging soon under the epidermal surface in various inhalant canals. A network of superficial translucent much larger exhalant canals leading to prominent oscula. Well-developed mesohyl with several layers of vacuolar cells in the ectosome. No sub-ectosomal cavities. Leuconoid aquiferous system with diplodal choanocyte chambers. High abundance of prokaryotic symbionts in the mesohyl.

Plakina doudou sp. nov. (Figure 1). Material examined. Holotype: Mus��um National d���Histoire Naturelle de Paris, France, MNHN DJV200: Grotte Chauve-Souris at 12 m depth, Anse Noire, La Martinique (14��32.024���N, 61��05.278���W). Collector: Thierry P��rez, 26 March 2016. Sample code: 160326- MT6 -TP2. GenBank accession number: MN 175680. Paratype: Mus��um National d���Histoire Naturelle de Paris, France, MNHN DJV201: Grotte Chauve-Souris at 12 m depth, Anse Noire, La Martinique. Collector: Thierry P��rez, 26 March 2016. Sample code: 160326- MT6 - TP3. GenBank accession number: MN 175681. Comparative material examined. Plakina arletensis Ruiz et al. 2017. MNHN DJV 177, Grotte Chauve-Souris, Anse Noire, La Martinique (14��32.024���N, 61��05.278���W). Collector: Thierry P��rez. Plakina elisa (Laubenfels, 1936). USMN 22237, Lemon Bay, Margarita Island, Fort Randolph, Panama Canal (9��22.817N, 79��55.683W). Collector: Max Walker de Laubenfels. Etymology. The species name ���doudou��� comes from the Antillais dialect and refers to a beloved person. In French, ���doudou��� is the name given to a child���s cuddly toy, which is often a piece of soft fabric or a stuffed animal that the child holds for comfort in the darkness of the night. Our new species was first observed in photographs taken of the dark cave wall. Because it looks fairly similar to a piece of soft fabric, and because we could not bring ourselves to abandon the crusty little sponge in that dark cave���no more than a child would be able to abandon their teddy���we named the species ���doudou���. Diagnosis. Thinly encrusting Plakina with a microlobate surface and whitish color in vivo. Skeleton made of diods, triods, calthrops, monolophose triods and monolophose, dilophose and trilophose calthrops. Mesohyl with no specialized cells and a low abundance of prokaryotic symbionts. Description. The new species is small and thinly encrusting, 2 mm to 10 mm large, and 2 mm to 3 mm thick. Its consistency is soft and fragile. Its color in vivo is whitish, becoming slightly cream after fixation in alcohol. It has rounded and irregular edges, and is without a marginal canal. The surface is irregular, microlobate, especially in the smallest individuals, and is densely punctuated by small inhalant openings. Oscules are circular, slightly elevated, up to 5 mm in diameter with a perioscular membrane. Skeleton. The skeleton is dense with an alveolar arrangement formed by randomly distributed spicule types of all sorts. However, lophose calthrops tend to be concentrated at the boundaries with the external medium (base, surface and around aquiferous canals) (Figure 2 A���B). Spicules (Table 1). Diods are abundant, regular, straight, smooth, with blunt ends and variable centrotylote-like central irregularity (Figure 2C); their total length/width: 31.7���39.7���59.4/3.2���3.6��� 5.6 ��m. n���measured spicules in total. MNHN���Mus��um National d���Histoire Naturelle. H���Holotype. P���Paratype. Triods are abundant, regular, Y-shaped and uniplanar, smooth, with blunt ends (Figure 2D). Their actines measure 14.2���15.7���19.1/2.3���2.8���4.0 ��m. Calthrops are abundant, regular, and smooth with blunt ends, the fourth actine being reduced to a small button (Figure 2E); their actines measure 9.7���13.7���21/1.6���2.8��� 5.1 ��m. Monolophose triods are rare, regular, with one lophose actine ramifying in 3���7 rays, sometimes with terminal spines. Basal (non-lophose) actines are regular with blunt ends (Figure 2F); their total length: 5.3���20.5��� 31.7 ��m. Monolophose calthrops are common, regular, with lophose actines ramifying in 3���6 rays that may have terminal spines (ramification pattern 1m, 2d, ts; see Muricy & D��az 2002). Non-lophose actines are regular with blunt or terminally spined tips (Figure 2G); their total length: 12���17.7��� 24.6 ��m. Dilophose calthrops are abundant, regular, with lophose actines ramifying medially in 3���5 rays that may have terminal spines (ramification pattern 1m, 2d, ts). Non-lophose actines are regular with blunt or terminally spined tips (Figure 2H); their total length: 15.6���19.9��� 28.3 ��m. Trilophose calthrops are rare, irregular, with two regular lophose actines ramifying medially in 3���4 rays that may have terminal spines (ramification pattern 1md, 2d, ts) and one lophose actine ramifying in 2 rays with blunt or terminally spined tips (ramification pattern 1m, ts). Basal (non-lophose) actines are regular with blunt or terminally spined tips (Figure 2I); their basal actines measure 5.8���7.8���10/1.5���2.3��� 3.3 ��m. Internal anatomy (Figure 3). The aquiferous system is leuconoid, with irregularly positioned inhalant and exhalant canals. There are no ectosomal lacunae, but there is a well-developed system of basal cavities which can be up to 300 ��m high. Choanocyte chambers are eurypylous, ovoid, 30 to 60 ��m in diameter, with 16 to 33 choanocytes recorded per section. The ectosome is thin, only 0.3 to 3 ��m in thickness. The mesohyl volume is approximately equal to the choanocyte chamber volume. Cytology. Choanocytes are ovoid (5.3���7.2 ��m long; 3.3���3.6 ��m thick). The choanocyte nucleus is spherical and located in basal position (1.5���2.8 ��m in diameter). The cytoplasm is dense, with numerous inclusions, mostly located in apical position. Choanocytes are flagellated (Figure 4 A���B). Apopylar cells are rounded to ovoid (6.2���7.4 ��m in diameter) with numerous rounded cytoplasmic inclusions (Figure 4C). Exopinacocytes are fusiform (15.3���17 ��m long; 0.4���2.4 ��m thick), with a large nucleus and small cytoplasmic inclusions, apparently without flagella (Figure 4D). Endopinacocytes are fusiform (12.4���13.8 ��m long; 0.4���1.5 ��m thick) and flagellated, with a large nucleus and some small cytoplasmic inclusions (Figure 4E). Symbiotic prokaryotes. The new species is considered to be a low microbial abundance (LMA) sponge. TEM allowed to distinguish one dominant extracellular morphotype, a curved rod form (0.8���2 ��m long; 0.2���0.25 ��m thick) with a simple thin wall (0.03���0.05 ��m thick), that was randomly dispersed in the mesohyl. The small spherical and ovoid forms were interpreted as transversal sections of this dominant morphotype (Figure 4F). Reproduction. Embryos and pre-larvae were observed in both specimens prepared for cytology (Figs. 3A and 3 E���F). Their diameter measured between 60 and 97 ��m. On semi-thin sections of the holotype, some premature oocytes were also observed (Figure 3B). DNA analysis of studied species. For all species considered in this study, GenBank accession numbers are presented in Table 2. Two well-supported clades represent the two families of Homoscleromorpha. In this tree, most of the Plakinidae genera seem to be monophyletic. The only genus without a skeleton, Aspiculophora Ruiz et al., 2017 forms a well-supported clade with Tetralophophora R��tzler et al., 2014. The Plakina group appears to be paraphyletic with three well-supported groups represented in the phylogenetic tree. The type species P. monolopha groups together with Corticium candelabrum Schmidt, 1862. A second group includes P. jani Muricy et al., 1998 and P. arletensis, while the third includes Plakina doudou sp. nov., P. trilopha Schulze, 1880 and P. crypta Muricy et al., 1998. The two individuals of the new species which were considered for this analysis present identical sequences. Ecology. Plakina doudou sp. nov. is a sciaphilic species that forms tiny whitish crusts with a patchy distribution on the vertical walls of a shallow-water cave. In this cave, the hydrodynamics is always high, from the entrance to the back of the cave. This new species was found to live in syntopy with P. arletensis, from 10 to 12 m depth, in the darkest part of the cave. No signs of epibiosis or predation were observed., Published as part of Grenier, Marie, Ruiz, Cesar, Lage, Anaira & Perez, Thierry, 2020, New cave-dwelling Plakina (Plakinidae, Homoscleromorpha, Porifera) from Martinique Island (French Antilles), pp. 92-104 in Zootaxa 4729 (1) on pages 94-99, DOI: 10.11646/zootaxa.4729.1.6, http://zenodo.org/record/3629044, {"references":["Ruiz, C., Muricy, G., Lage, A., Domingos, C., Chenesseau, S. & Perez, T. (2017) Descriptions of new sponge species and genus, including aspiculate Plakinidae, overturn the Homoscleromorpha classification. Zoological Journal of the Linnean Society, 179 (4), 707 - 724.","Laubenfels, M. W. de (1936) A comparison of the shallow-water sponges near the Pacific end of the Panama Canal with those at the Caribbean end. Proceedings of the United States National Museum, 83 (2993), 441 - 466. https: // doi. org / 10.5479 / si. 00963801.83 - 2993.441","Muricy, G. & Diaz, M. C. (2002) Order Homosclerophorida Dendy, 1905, Family Plakinidae Schulze, 1880. In: Hooper, J. N. A & Van Soest, R. W. M. (Eds.), Systema Porifera: a guide to the classification of Sponges. Kluwer Academic / Plenum Publishers, New York, pp. 71 - 82. https: // doi. org / 10.1007 / 978 - 1 - 4615 - 0747 - 5 _ 6","Rutzler, K., Piantoni, C., van Soest, R. W. M. & Diaz, M. C. (2014) Diversity of sponges (Porifera) from cryptic habitats on the Belize barrier reef near Carrie Bow Cay. Zootaxa, 3805 (1), 1 - 129. https: // doi. org / 10.11646 / zootaxa. 3805.1.1","Schmidt, O. (1862) Die Spongien des Adriatischen Meeres. Wilhelm Engelmann, Leipzig, 88 pp.","Muricy, G., Boury-Esnault, N., Bezac, C. & Vacelet, J. (1998) Taxonomic revision of the Mediterranean Plakina Schulze (Porifera, Demospongiae, Homoscleromorpha). Zoological Journal of the Linnean Society, 124, 169 - 203. https: // doi. org / 10.1111 / j. 1096 - 3642.1998. tb 00572. x","Schulze, F. E. (1880) Untersuchungen uber den Bau und die Entwicklung der Spongien. Neuten Mittheilung. Die Plakiniden. Zeitschrift fur wissenschaftliche Zoologie, 34, 407 - 451."]}

Genus Oscarella Vosmaer, 1884 Type species: Halisarca lobularis Schmidt, 1862 (by monotypy). (Oscaria) Vosmaer, 1881: 163 (preocc. by Oscaria Gray, 1873 ���Reptilia); Oscarella Vosmaer, 1884: pl. 8 (explanation); 1887: 326 (nom. nov. for Oscaria Vosmaer). Octavella Tuzet and Paris, 1963: 88. Diagnosis: Homoscleromorphorida without skeleton, with a variable development of the ectosome. The aquiferous system has a sylleibid-like organization, with spherical to ovoid eurypylous or diplodal choanocyte chambers arranged around large exhalant canals (Muricy & Diaz 2002)., Published as part of Perez, Thierry & Ruiz, Cesar, 2018, Description of the first Caribbean Oscarellidae (Porifera: Homoscleromorpha), pp. 501-514 in Zootaxa 4369 (4) on page 504, DOI: 10.11646/zootaxa.4369.4.3, http://zenodo.org/record/1136414, {"references":["Vosmaer, G. C. J. (1884) Porifera. In: Bronn, H. G. (Ed.), Die Klassen und Ordnungen des Thierreichs, Volume II. C. F. Winter, Leipzig, pp. 65 - 176.","Schmidt, O. (1862) Die Spongien des adriatischen Meeres. Wilhelm Engelmann, Leipzig, 88 pp.","Vosmaer, G. C. J. (1881) Uber Leucandra aspera H. nebst allgemeinen Bemerkungen uber das Canalsystem der Spongien. Tijdschrift der Nederlandsche Dierkundige Vereeniging, 5, 144 - 166.","Gray, J. (1873) Notes on mud-tortoises (Trionyx Geoffroy), and on the skulls of the different kinds. Proceedings of the Zoological Society of London, 1873, 38 - 72.","Tuzet, O. & Paris, J. (1963) Octavella galangaui n. g n. sp. Demospongiae, Oscarellidae de Banyuls-sur-Mer. Vie et Milieu, 1, 71 - 89.","Muricy, G. & Diaz, M. C. (2002) Order Homosclerophorida Dendy, 1905, Family Plakinidae Schulze, 1880. In: Hooper, J. N. A & Van Soest, R. W. M. (Eds.), Systema Porifera: a guide to the classification of Sponges. Kluwer Academic / Plenum Publishers, New York, pp. 71 - 82. https: // doi. org / 10.1007 / 978 - 1 - 4615 - 0747 - 5 _ 6"]}

Oscarella filipoi sp. nov. Holotype: Mus��um National d���Histoire Naturelle de Paris, MNHN���DJV193: Martinique, Le Diamant, Caribbean Sea. Site �� Tunnel du Diamant �� (14��26.556' N, 61��2.408' W), 10 m depth, on a vertical wall of the tunnel, date 11/ 06/2011. Sample code: 120325 -MT1TP14 collector T. P��rez (Fig. 2). GenBank accession number: KX3482268. Paratype 1: Mus��um National d���Histoire Naturelle de Paris, MNHN���DJV194: Martinique, Le Diamant, Caribbean Sea. Site �� Grotte Fer �� Cheval �� (14��27.882' N, 61��01.162 W), 17 m depth, overgrowing an octocoral in the cave entrance, date 25/03/2012. Sample code: 120325 -MT4bTP01, collector T. P��rez. Paratype 2: Mus��um National d���Histoire Naturelle de Paris, MNHN���DJV195: Saint Martin, Caribbean Sea. Site �� Rocher Cr��ole �� (18��07.038' N, ' 063��03.419' W), 10 m, under an overhang, date 26/05/2015. Sample code: 150526 -SN3CR08 collector C. Ruiz. Other material examined: Martinique, 131203 -MT3CR1, Grotte Couleur at 8 m depth, Anses d'Arlet, collector C. Ruiz; 120325 -MT1TP12, 120325 -MT1TP13, 120325 -MT1TP14, Tunnel du Diamant at 15 m depth, collector T. P��rez. This material is kept in the collection of the Station Marine d���Endoume (Marseille���France). Etymology: the new species is dedicated to Philippe Th��lamon, a resourceful diver of Anses d���Arlet. Known by his nickname ���Filipo���, he is deeply involved in nature conservation and the promotion of Martinique���s marine biodiversity. Filipo was the first to take us to the type locality of the new species. Diagnosis. The largest Oscarella recorded world-wide, covering up to 1m ��, inhabiting shaded habitats. Color from purple to yellow and light green, with the largest specimens always purple, thick, with a pale-green base. Large specimens are often associated to tiny hydroids. Thick ectosome, especially in the basal part, is mostly devoid of cells. Ovoid to spherical eurypylous choanocyte chambers. Only one type of vacuolar cell is abundant and is grouped in clusters in the mesohyl. Description. External morphology: An encrusting sponge with irregular clathrate surface and small lobes. Size up to 1 m �� and 2���3 cm thick. Different color morphotypes have been observed: the most common is deep purple, but light green and light orange were also observed in natural conditions (Fig. 2). The surface is mostly colored while the basal part is pale or green in large specimens, turning green in all cases when put in alcohol. The consistency is soft, fragile and easy to tear. The surface presents small lobes that converge to oscula of about 1���4 cm diameter. Large and heavy specimens tend to partially detach from the substrate, often hanging from the ceiling of semi-dark caves and tunnels. Soft tissue organization: No spicule or fiber skeleton. The ectosome is 20 to 50 ��m in the apical zone, but can be considerably thicker than 100 ��m in the basal part (Fig. 3A). Inhalant canals, 13 to 22 ��m wide, often run perpendicular to the surface. The exhalant canals run towards a well-developed system of irregular basal cavities from 2 to 150 ��m in diameter before finally reaching the oscula of the sponge. Eurypylous choanocyte chambers are ovoid to spherical, from 30 to 72 ��m in diameter (Fig. 3). Apopylar cells are located around the apopyle of the choanocyte chambers. Basopinacocytes delimit the basal part from the substrate (Fig. 3). The ectosome is mostly devoid of cells, with only a few vacuolar cells distributed randomly underneath the pinacocytes (Fig. 3). Cytology: Choanocytes have a rather pyramidal shape, 3 to 7 ��m wide at the central part and 3.5 to 7 ��m high. (Fig.4). Their collar is 3 ��m wide, composed of about 30 microvilli. Their nucleus is basal, centrally positioned, and 1.5 to 3 ��m in diameter. Their cytoplasm usually contains 1 to 3 phagosomes of 0.8 to 1.7 ��m in diameter, osmiophilic inclusions and mitochondria. Apopylar cells also have a pyramidal shape, and are about the same size as the choanocytes. Pinacocytes are flat and flagellated, 7 to 12 ��m wide and 1 to 3 ��m high. Their nucleus is ovoid, up to 2 ��m in diameter. Several osmiophilic inclusions between 0.4 and 0.7 ��m were observed only in the cytoplasm of endopinacocytes (Fig. 4). No archaeocytes were observed in the mesohyl. One type of vacuolar cell, with an ovoid to irregular shape, 8 to 16 ��m in diameter, is quite abundant and is grouped in clusters in the mesohyl (Fig. 4). Its cytoplasm contains between 2 and 5 vacuoles, 3.5 to 10 ��m in diameter, and their content is always clear. No bacteriocytes were observed. A single morphotype of symbiotic prokaryote is distributed in the mesohyl. It has a bacillus morphology, 1 to 1.5 ��m long and 0.5 ��m in diameter, with a cell wall consisting of many layers of dense filaments (Fig. 4). Each bacteria is surrounded by a surface devoid of collagen fibers (Fig. 4). No reproductive elements were observed. Ecology. Oscarella filipoi sp. nov. was found in rather shallow waters, from 3 to 20 m depth. This new species prefers half-light conditions, and can thus be found on vertical walls of semi-dark marine caves, under overhangs, underneath rocks or inside crevices. The only sign of epibiosis is an undetermined tiny hydroids that grows into the lobes of the sponge, especially on large specimens. No sign of predation was observed. Taxonomic remarks. The new species cannot be confused with the previous aspiculate Homoscleromorpha described in the Caribbean, as it has very classic Oscarella external morphology: it is clathrate with a very soft consistency, whereas A. madinina, for instance, has a cushion or globulous shape with a gelatinous consistency. On the other hand, the aspiculate P. nathaliae is a leaf-like, thinly encrusting sponge, which is a rather classic external morphology for Plakina. According to the in situ photos available in previous reports of Oscarella in the Caribbean Sea, the new species may well have formerly been called O. lobularis (e.g. Vacelet 1998). The external morphology (color, consistency and aspect of the surface) of the smallest specimens of O. filipoi sp. nov. is indeed very similar to the Mediterranean species, but the largest specimens do not correspond to any previous reports of Oscarella. The largest specimens tend to detach from the substratum, allowing a part of the body to hang like a curtain. The mesohylar content of the new species is very different from that of O. lobularis, as it includes abundant clusters of vacuolar cells, a trait shared with O. tuberculata (Boury-Esnault et al. 1992)., Published as part of Perez, Thierry & Ruiz, Cesar, 2018, Description of the first Caribbean Oscarellidae (Porifera: Homoscleromorpha), pp. 501-514 in Zootaxa 4369 (4) on pages 504-506, DOI: 10.11646/zootaxa.4369.4.3, http://zenodo.org/record/1136414, {"references":["Boury-Esnault, N., Sole-Cava, A. M. & Thorpe, J. P. (1992) Genetic and cytological divergence between colour morphs of the Mediterranean sponge Oscarella lobularis Schmidt (Porifera, Demospongiae, Oscarellidae). Journal of Natural History, 26 (2), 271 - 284. https: // doi. org / 10.1080 / 00222939200770131"]}

Oscarella zoranja sp. nov. Holotype: Mus��um National d���Histoire Naturelle de Paris, MNHN���DJV196: Martinique, Anses d���Arlet, Caribbean Sea. Site �� Grotte Couleur �� (14��29.752��N, 61��05.407��W), 7 m depth, under an overhang, date 11/06/ 2011. Sample code: 110611 -MT3TP5, collector T. P��rez (Fig.5). GenBank accession number: KX3482266. Paratype 1: Mus��um National d���Histoire Naturelle de Paris, MNHN���DJV197: Guadeloupe, Caribbean Sea. Site ��� Grotte aux Barracudas ���, (16��27.301'N, 61�� 32.253'W), 19 m depth, under an overhang, date 15/02/2012. Sample code: GR26HOM1, collector A. Ereskovsky. Paratype 2: Mus��um National d���Histoire Naturelle de Paris, MNHN���DJV198: Martinique, Le Diamant, Caribbean Sea. Site �� Grotte Zeb �� (14��27.832' N, 61��01.065' W), 19 m depth, on a vertical wall at the entrance of the cave, date 15/05/2016. Sample code: 150516 -MT4CR13, collector C. Ruiz. Other material examined: Martinique, 131203 -MT3CR2, Anses d'Arlet, Grotte Couleur at 8 m depth. collector C. Ruiz; 150516 -MT4CR4, 150516 -MT4CR13, 150516 -MT4CR8 Le Diamant, Grotte Zeb at 19 m depth, collector C. Ruiz; 110611 -MT4TP12, 110611 -MT4TP5, Le Diamant, Grotte Zeb at 19 m depth, collector T. P��rez; 110613 - MT1TP7 Le Diamant, tunnel du Diamant at 15 m depth, collector T, P��rez. Guadeloupe, 150516 - MT8CR4, GR26HOM9, GR27HOM16, GR26HOM4, Grotte aux Barracudas at 19 m depth, collector A. Ereskovsky; GR34HOM29, GR30HOM29, GR26HOM1, GR26HOM8, GR27HOM20 Grotte la Cath��drale at 18 m depth, collector A. Ereskovsky. This material is kept in the collection of the Station Marine d���Endoume (Marseille���France). Etymology: From the creole zoranj (orange), the species name thus refers to the color of the new species. Diagnosis: Oscarella inhabiting shaded habitats. Orange color. Smooth, regularly lobate surface and rather cartilaginous consistency. Ovoid to spherical eurypylous choanocyte chambers. A single type of vacuolar cell, containing up to 10 vacuoles, and one type of spherulous cell. Description. External morphology: A sponge with regular lobate surface which can be up to 15 to 20 cm large and 1 to 3 cm thick. The consistency is soft, and the sponge is easily removed from the substrate. The color in vivo is always a nuance of orange. The sponge does not exude any substance in contact with air, nor does its color change in alcohol. Its surface is smooth, and it presents between 1 and 3 oscula of about 12 mm in diameter. The lobes are small, rounded and regular, and only a few of them have inhalant ostia with a flared-out margin. Soft tissue organization: No spicule or fibers. The ectosome is thick, from 30 to 83 ��m. The inhalant canals (13 to 19 ��m) run perpendicular to the surface. Exhalant canals run towards a well-developed system of irregular basal cavities leading to the oscula. The eurypylous choanocyte chambers are ovoid to spherical, with diameters between 30 and 72 ��m (Fig. 6 and 7). The apopyle is surrounded by apopylar cells. Cytology: Choanocytes are ovoid to pyramidal, 2.2 to 5 ��m large and 4 to 6 ��m high. (Fig.7B). Their collar averages 3 ��m wide and is composed of about 30 microvilli. Their nucleus, 1.5 to 2.5 ��m in diameter, is in central to basal position. The cytoplasm usually contains 1 to 3 phagosomes, 0.6 to 1.7 ��m in diameter, osmiophilic inclusions and mitochondria. Apopylar cells are ovoid to pyramidal in shape and of the same size as the choanocytes (Fig. 7). Their nucleus is centrally positioned and 1.5 to 2.5 ��m in diameter. Small vacuoles up to 2 ��m wide are present in their cytoplasm. Pinacocytes are flat and flagellated, 7 to 12 ��m large and 1 to 3 ��m high. Their ovoid nucleus is up to 2 ��m in diameter. Several osmiophilic inclusions between 0.4 and 0.7 ��m were observed only in the cytoplasm of endopinacocytes. No archaeocyte was observed, although two types of cells with vacuoles were recorded in the mesohyl and in the ectosome. Both types are ovoid to irregular, from 8 to 16 ��m in diameter, with a cytoplasm containing between 2 and 10 vacuoles of 3.5���10 ��m in diameter (Fig.7). The only difference between the two types lies in the content of the vacuoles: the first type can be defined as a vacuolar cell, with almost empty vacuoles (Fig. 7), whereas the second type is a spherulous cell with vacuoles occupied by electron- dense materials. Prokaryotic cells are quite abundant in the mesohyl. The main morphotype is a bacilluslike shape, 1 to 1.5 ��m long and 0.5 ��m in diameter (Fig. 7). The cell wall consists of many layers of dense filaments, and the cytoplasm can be dense to electrons. Each bacterium is surrounded by a layer devoid of collagen fibrils. No reproductive element was observed. Ecology. Oscarella zoranja sp. nov. can be found in the same habitats as O. filipoi, on vertical walls of semidark caves, tunnels, overhangs and small crevices. This species was found from shallow waters down to 50 m depth in a cave off the Rocher du Diamant in Martinique. This species is never subject to epibiosis and no sign of predation was observed. Taxonomic remarks. Oscarella zoranja sp. nov. has very classic Oscarella external morphology, lobate and with a rather cartilaginous consistency compared to O. filipoi sp. nov., again removing any possibility for confusion with the previous aspiculate Homoscleromorpha described in the Caribbean Sea (Ruiz et al. 2017). This species has the same external morphology and consistency as O. tuberculata, but the new species differs in color and in its mesohylar cells. Unlike both O. tuberculata and O. filipoi sp. nov., this new species does not present clusters of vacuolar cells. DNA analysis. The positioning of the two new Oscarellidae within the Homoscleromorpha phylogeny was achieved after sequencing all examined individuals and downloading some GenBank sequences (Fig. 8). The two families of Homoscleromorpha (Gazave et al. 2010) are well supported in the phylogenetic reconstruction. Oscarellidae is composed of two main clades, and both new species clearly belong to the clade containing the type species of the family Oscarella lobularis. Oscarella filipoi sp. nov. is the closest to the type species, its sequences of the I3 -M11 CO1 fragment differing by 25 and 26 base-pairs from O. lobularis and O. tuberculata, respectively. Oscarella zoranja sp. nov. is not included in the O. filipoi sp. nov. clade and the type species of the family, because its sequences differ by 32 to 35 base-pairs on average from the previous group of species. Oscarella zoranja sp. nov. presents the highest genetic variability recorded among the Homoscleromorpha with this molecular marker, with up to 8 different base pairs between the sequenced individuals, compared with the single base-pair that differs between Oscarella tuberculata (Schmidt, 1868) and O. lobularis. However, our analyses of the morphology of a great number of individuals of O. zoranja sp. nov. failed to reveal any trait which might support this variability., Published as part of Perez, Thierry & Ruiz, Cesar, 2018, Description of the first Caribbean Oscarellidae (Porifera: Homoscleromorpha), pp. 501-514 in Zootaxa 4369 (4) on pages 507-509, DOI: 10.11646/zootaxa.4369.4.3, http://zenodo.org/record/1136414, {"references":["Gazave, E., Lapebie, P., Renard, E., Vacelet, J., Rocher, C., Ereskovsky, A. V., Lavrov, D. V. & Borchiellini, C. (2010) Molecular Phylogeny Restores the Supra-Generic Subdivision of Homoscleromorph Sponges (Porifera, Homoscleromorpha) PLOS ONE, 5, e 14290. https: // doi. org / 10.1371 / journal. pone. 0014290","Schmidt, O. (1868) Die Spongien der Kuste von Algier. Mit Nachtragen zu den Spongien des Adriatischen Meeres (Drittes Supplement). Wilhelm Engelmann, Leipzig, pp. 1 - 44."]}

Vansoestia, gen. nov. Diagnosis. Ianthellidae represented by individuals with a thin (1���4 mm) encrusting growth form that presents a cellularized cortex of variable thickness (10���200 ��m) composed of a collagenous matrix and various types of cells with inclusions (i.e. granular, spherulous, and/or vacuolar). Abundant subdermal canals and lacunae are found immediately underneath the cortex. The choanosome consists of numerous aquiferous canals, a mesohyl where two or three types of cells with inclusions can be distinguished, and oval eurypylous choanocyte chambers 20���50 ��m, all supported with abundant fibrillar collagen. Type species: Vansoestia caribensis gen. nov. sp. nov. Material examined. All specimens studied were found in coral reefs from Bocas del Toro, Panama, between 10���20 m in depth. This species grows over dead coral and other organisms, in open and cryptic reef habitats. Holotype: USNM 1133773, Buoy 19 (N 9 �� 18.11, W 82 �� 17.66), Bocas del Toro, Panama (P 67), 10 m deep, coll: M.C. D��az and R.W. Thacker; 7 / 18 / 2009 Paratypes: USNM 1133782, Buoy 19 (N 9 �� 18.11, W 82 �� 17.66), Bocas del Toro, Panama (P 76), 15 m deep, coll: M.C. D��az and R.W. Thacker; 7 / 18 / 2009; USNM 1204851 (P 12 x 342), Punta Caracol (N 9 �� 22.66, W 82 �� 18.19), 15 m deep, coll: M.C. D��az and S.A. Pomponi, 8 / 8 / 2012. Additional material. P 12 x 402, and P 12 x 403 were consumed in histological, or TEM preparations. Etymology. The species is named in honor of Dr. Rob van Soest, an essential contributor to the understanding of Demospongiae, including Verongida, in the Caribbean and worldwide. Description. External morphology: The sponge is soft, thinly encrusting (1���4 mm thick), orange to yellow in color internally and externally. Color turns slowly brown to purple in ethanol. The sponge grows over dead coral or over other organisms, particularly other sponges (Figure 1). Its surface is dominated by thin reticulated subdermal canals (3���8 mm wide) that branch and decrease in width away from the oscules (0.5���1 cm wide). Small ostia (0.4��� 0.8 mm wide) are dispersed between subdermal canals. The soft and fragile consistency of this sponge reflects the lack of a reticulate fiber skeleton. Internal morphology (Figures 2���4). There is a clear separation between ectosome and choanosome (Figure 2 A). The ectosome is a collagenous cortex of variable thickness (10���200 ��m), with collagen in the form of an amorphous matrix containing loose cells with inclusions (Figure 2 A, B), and an external cuticle (Figure 3 A). Large channels and lacunae (subdermal spaces) are observed immediately underneath the ectosome (Figure 2 A). The choanosome consists of densely arranged oval-shaped choanocyte chambers (20���40 ��m in diameter) (Figure 2 A, C), and a mesohyl reinforced by collagen fibrils arranged in strands (Figure 3 B, C), packed with various types of cells with inclusions, and with abundant aquiferous canals. The chambers are densely and homogeneously distributed in some areas (Figure 2 A, C), and rare in others that are instead densely packed by conglomerates of cells (Figure 3 D). Choanocytes (4���6 ��m in diameter) appear oval to triangular in shape (Figure 2 D). Larger cells with inclusions of various shapes and sizes (4���12 ��m in diameter) can be observed in both the mesohyl and the ectosome (Figures 2���3). The largest cells with inclusions (Ci 1) are widespread in the mesohyl, in the cortex, and lining canals (Figure 3 B and 3 D). There are some canals lined by these large cells with inclusions (Figure 3 D), and others without them (Figure 3 C). TEM sections allowed further distinction of the various types of cells with inclusions, and the observation of archaeocytes, choanocytes, and collagen fibrils. Spherulous cells 1 (Figure 4 A, B and D) are ovoid to roundish slightly deformed (6���10 ��m in diameter) with spherules (0.7���2 ��m wide), containing microgranular inclusions that are dense but grey or black in color (0.06���0.15 ��m in diameter), with a clear round nucleus (1.3���2 ��m in diameter). By the size and distribution of spherules, these cells probably correspond to the cells with inclusions 1 (Sc 1) observed in the histological cross sections (Figures 2���3). Spherulous cells 2 (Figure 4 B) are similar in size and shape of Sc 1, but their spherules are larger and ellipsoid in shape (0.1���0.3 ��m in diameter), and electron dense dark. These cells might represent a different stage of the spherulous cell 1. A third type, which seems like vacuolar cells (Figure 4 C), occurs with variable shapes, smaller size (5���8 ��m in diameter), and containing a single round, dark dense granule (0.4���0.8 ��m in diameter) within each vacuole (1���1.5 ��m in diameter). By the shape and size of the granules, these cells likely correspond to the cell with inclusion 2 observed in the histological cross sections. Finally, a microgranular cell with membrane-bound inclusions with striated content, was observed once (Figure 4 D). A thick layer of collagen fibrils (Co) with loose bacteria surrounds the choanocyte chambers and long cytoplasmic projections could be seen in some choanocytes (Figure 4 E). One choanocyte with a basal nucleolated nucleus was observed (Figure 4 F). Remarks. The delicate and thin specimens of Vansoestia caribensis have been found in Bocas del Toro, Panama, since 2006; however, only the slow oxidation observed when specimens were placed into alcohol suggested an affinity to verongids. Due to the lack of a fiber skeleton, we initially affiliated this sponge to the genus Hexadella. Histological observations corroborated its ianthellid nature (large, sac-shaped choanocyte chambers), but its distinct identity and closest affinity to the known sequences of fiber-bearing ianthellid genera from the Western Tropical Pacific appeared after analyzing 18 S and 28 S ribosomal gene sequences (Redmond et al., 2013; Thacker et al., 2013). Its genetic distance from the only previously known fiber-less verongid genus, Hexadella, prompted the need to erect a new genus to classify this species. This biological record constitutes the first member of family Ianthellidae ever encountered in the Caribbean Sea. There is a striking similarity between V. caribensis gen nov. sp. nov. and the external appearance of Hexadella pruvoti Topsent, 1896 (Reveillaud et al., 2012), particularly with respect to the abundant subdermal canals converging in a wide oscule, and its yellowish coloration. However, 18 S and 28 S gene sequence analyses confirmed the very distinct nature of these two species. A cellularized cortex of variable thickness (10���200 ��m thick) composed of amorphous collagen and various types of cells is present in V. cari bensis gen. nov. sp. nov. and forms an important morphological difference between these two genera, since Hexadella possesses a thinner cortex with a 1 ��m thick cuticle. A well-developed cellularized cortex might represent a potential synapomorphy between Vansoestia gen. nov., Ianthella, and Anomoianthella (Bergquist, 1980, 1995; Bergquist and Kelly-Borges, 1995; Bergquist and Cook, 2002; present study). Indeed, Bergquist, (1995) and Bergquist and Kelly-Borges (1995) described a collagenous ectosome (70 to 300 ��m thick) containing cells for all Ianthella species and a cellularized cuticle for Anomoianthella species (Bergquist, 1980). Together with the presence of a collagen-reinforced cortex combined with a cuticle, the high degree of reinforcement of the choanosome with collagen is also a characteristic shared by Vansoestia gen. nov., Ianthella and Anomoianthella. Some similarities among the spherulous cells of V. caribensis gen. nov. sp. nov., and other verongids were also noticed (Vacelet, 1967). The cells with striated membrane-bound bodies are very similar to cells observed in Aplysina aerophoba by Maldonado (2009). The dark granules found in cells of Vansoestia gen. nov. might represent glycogen granules (Maldonado, 2009), or they might contain brominated compounds (Thompson, 1986) like has been found for microgranular and spherulous cells of two different Aplysina species. The large diversity of cells with inclusions, and their similarities with species of Hexadella and other verongid genera invites continued research to understand the morphology and physiological functions of these cells and their products. Phylogenetic remarks. 18 S and 28 S sequences demonstrate that this fiber-less member of Ianthellidae is a sister group to the clade that includes Ianthella and Anomoianthella. (Redmond et al., 2013; Thacker et al., 2013). Figure 5 summarizes the current phylogenetic interpretation of the relationships among verongid genera based on the latest molecular, and morphologic studies of the group (Erwin and Thacker, 2007; Erpenbeck et al., 2012; D��az et al., 2013; Redmond et al., 2013; Thacker et al., 2013). The two sister clades make up the subclass Myxospongiae, one containing the amended Verongida (after Redmond et al., 2013) and the other containing Chondrilla and Halisarca (Order Chondrillida sensu Redmond et al., 2013). All verongids are grouped in a strongly supported monophyletic clade (Figure 5, clade 1), which shares the presence of collagen fibrils forming bundles either in the cortex, in the mesohyl, or within fibers. Chondrosia (family Chondrosiidae) forms a wellsupported sister clade to all other verongids (Figure 5, clade 2), and is represented by sponges with extremely high collagen content, a thick (> 1 mm thick) ���collagenous cortex���, and a fiber-less body. The rest of the verongids form a highly supported clade (Figure 5, clade 3), containing all taxa that produce brominated secondary metabolites and have abundant spherulous cells. Basal within this group, a highly supported clade (Figure 5, clade 4) contains all Hexadella species which share eurypylous choanocyte chambers, a thin cuticle (1���2 ��m) and a very thin ectosome. The next clade (Figure 5, clade 5) is a moderately supported clade containing all non- Hexadella verongids. Within clade 5, two clades are distinguished: a moderately (85 %) supported clade (Figure 5, clade 6) containing Vansoestia gen. nov. (skeleton less) and the fiber bearing Pacific taxa of genera Ianthella and Anamoianthella, and a moderately to highly supported clade (Figure 5, clade 7) including all the taxa possessing diplodal choanocyte chambers. Within clade 7 (Figure 5), a clearly monophyletic group of sponges (clade 8) contains all Aplysina species, whereas a poorly supported clade (clade 9) contains at least six genera (Aiolochroia, Aplysinella, Porphyria, Pseudoceratina, Suberea, Verongula) and an undescribed genus from Moorea (D��az et al., 2013). The Verongida taxa with eurypylous, sac-shaped choanocyte chambers are placed in two distinct clades (Figure 5, clades 4 and 6), demonstrating that this feature is paraphyletic within Verongida. Current studies suggest the classification of Verongida comprises four main clades: (1) a clear monophyletic group containing all Aplysina species studied, and representatives of all Aplysinellidae, and Pseudoceratiniidae genera; (2) a clade that contains Ianthella, Anomoianthella, and Vansoestia gen. nov., but excludes Hexadella, which should be defined by an amended family Ianthellidae; (3) a clade that presently contains only Hexadella and that should be erected as a new family; and (4) a clade containing the family Chondrosiidae sensu Redmond et al. (2013). We demonstrate here that the suprageneric classification of Verongida must be further revised in order to reflect our current knowledge of phylogenetic relationships among the genera of Myxospongiae. Considering the diagnostic characters that we have in hand, a thorough comparative review of the histological and ultrastructural features of representatives of each genus is definitely needed to improve the taxonomic diagnoses of these taxa., Published as part of D��az, Maria C., Thacker, Robert W., Redmond, Niamh E., Perez, Thierry & Collins, Allen G., 2015, Vansoestia caribensis gen. nov., sp. nov.: first report of the family Ianthellidae (Verongida, Demospongiae) in the Caribbean, pp. 403-412 in Zootaxa 3956 (3) on pages 405-411, DOI: 10.11646/zootaxa.3956.3.5, http://zenodo.org/record/240004, {"references":["Topsent, E. (1896 a) Materiaux pour servir a l'etude de la faune des spongiaires de France. Memoires de la Societe zoologique de France, 9, 113 - 133","Reveillaud, J., Allewaert, C., Perez, T., Vacelet, J., Banaigs, B. & Vanreusel, A. (2012) Relevance of an integrative approach for taxonomic revision in sponge taxa: case study of the shallow-water Atlanto-Mediterranean Hexadella species (Porifera: Ianthellidae: Verongida). Invertebrate Systematics, 26, 230 - 248. http: // dx. doi. org / 10.1071 / IS 11044","Bergquist, P. R. (1980) A revision of the supraspecific classification of the orders Dictyoceratida, Dendroceratida and Verongida (class Demospongiae). New Zealand Journal of Zoology, 7 (4), 443 - 503.","Bergquist, P. R. & Kelly-Borges, M. (1995) Systematics and biogeography of the genus Ianthella (Demospongiae: Verongida: Ianthellidae) in the South-West Pacific. The Beagle, Records of the Museums and Art Galleries of the Northern Territory, 12, 151 - 176.","Vacelet J. (1967) Les cellules a inclusions de l'eponge cornee Verongia cavernicola. Journal de Microscopie, 6, 237 - 240.","Maldonado, M. (2009) Embryonic development of verongid demosponges supports the independent acquisition of spongin skeletons as an alternative to the siliceous skeleton of sponges. Biological Journal of the Linnaean Society, 97, 427 - 447. http: // dx. doi. org / 10.1111 / j. 1095 - 8312.2009.01202. x","Erwin, P. M. & Thacker, R. W. (2007) Phylogenetic analyses of marine sponges within the order Verongida: a comparison of morphological and molecular data. Invertebrate Biology, 126, 220 - 234. http: // dx. doi. org / 10.1111 / j. 1744 - 7410.2007.00092. x","Erpenbeck, D., Sutcliffe, P., Cook, S., Dietzel, A., Maldonado, M., van Soest, R. W. M., Hooper, J. & Worheide, G. (2012) Horny sponges and their affairs on the phylogenetic relationships of keratose sponges. Molecular Phylogenetics and Evolution, 63, 809 - 816. http: // dx. doi. org / 10.1016 / j. ympev. 2012.02.024"]}

Vansoestia, gen. nov. Diagnosis. Ianthellidae represented by individuals with a thin (1–4 mm) encrusting growth form that presents a cellularized cortex of variable thickness (10–200 µm) composed of a collagenous matrix and various types of cells with inclusions (i.e. granular, spherulous, and/or vacuolar). Abundant subdermal canals and lacunae are found immediately underneath the cortex. The choanosome consists of numerous aquiferous canals, a mesohyl where two or three types of cells with inclusions can be distinguished, and oval eurypylous choanocyte chambers 20–50 µm, all supported with abundant fibrillar collagen. Type species: Vansoestia caribensis gen. nov. sp. nov. Material examined. All specimens studied were found in coral reefs from Bocas del Toro, Panama, between 10–20 m in depth. This species grows over dead coral and other organisms, in open and cryptic reef habitats. Holotype: USNM 1133773, Buoy 19 (N 9 ° 18.11, W 82 ° 17.66), Bocas del Toro, Panama (P 67), 10 m deep, coll: M.C. Díaz and R.W. Thacker; 7 / 18 / 2009 Paratypes: USNM 1133782, Buoy 19 (N 9 ° 18.11, W 82 ° 17.66), Bocas del Toro, Panama (P 76), 15 m deep, coll: M.C. Díaz and R.W. Thacker; 7 / 18 / 2009; USNM 1204851 (P 12 x 342), Punta Caracol (N 9 ° 22.66, W 82 ° 18.19), 15 m deep, coll: M.C. Díaz and S.A. Pomponi, 8 / 8 / 2012. Additional material. P 12 x 402, and P 12 x 403 were consumed in histological, or TEM preparations. Etymology. The species is named in honor of Dr. Rob van Soest, an essential contributor to the understanding of Demospongiae, including Verongida, in the Caribbean and worldwide. Description. External morphology: The sponge is soft, thinly encrusting (1–4 mm thick), orange to yellow in color internally and externally. Color turns slowly brown to purple in ethanol. The sponge grows over dead coral or over other organisms, particularly other sponges (Figure 1). Its surface is dominated by thin reticulated subdermal canals (3–8 mm wide) that branch and decrease in width away from the oscules (0.5–1 cm wide). Small ostia (0.4– 0.8 mm wide) are dispersed between subdermal canals. The soft and fragile consistency of this sponge reflects the lack of a reticulate fiber skeleton. Internal morphology (Figures 2–4). There is a clear separation between ectosome and choanosome (Figure 2 A). The ectosome is a collagenous cortex of variable thickness (10–200 µm), with collagen in the form of an amorphous matrix containing loose cells with inclusions (Figure 2 A, B), and an external cuticle (Figure 3 A). Large channels and lacunae (subdermal spaces) are observed immediately underneath the ectosome (Figure 2 A). The choanosome consists of densely arranged oval-shaped choanocyte chambers (20–40 µm in diameter) (Figure 2 A, C), and a mesohyl reinforced by collagen fibrils arranged in strands (Figure 3 B, C), packed with various types of cells with inclusions, and with abundant aquiferous canals. The chambers are densely and homogeneously distributed in some areas (Figure 2 A, C), and rare in others that are instead densely packed by conglomerates of cells (Figure 3 D). Choanocytes (4–6 µm in diameter) appear oval to triangular in shape (Figure 2 D). Larger cells with inclusions of various shapes and sizes (4–12 µm in diameter) can be observed in both the mesohyl and the ectosome (Figures 2–3). The largest cells with inclusions (Ci 1) are widespread in the mesohyl, in the cortex, and lining canals (Figure 3 B and 3 D). There are some canals lined by these large cells with inclusions (Figure 3 D), and others without them (Figure 3 C). TEM sections allowed further distinction of the various types of cells with inclusions, and the observation of archaeocytes, choanocytes, and collagen fibrils. Spherulous cells 1 (Figure 4 A, B and D) are ovoid to roundish slightly deformed (6–10 µm in diameter) with spherules (0.7–2 µm wide), containing microgranular inclusions that are dense but grey or black in color (0.06–0.15 µm in diameter), with a clear round nucleus (1.3–2 µm in diameter). By the size and distribution of spherules, these cells probably correspond to the cells with inclusions 1 (Sc 1) observed in the histological cross sections (Figures 2–3). Spherulous cells 2 (Figure 4 B) are similar in size and shape of Sc 1, but their spherules are larger and ellipsoid in shape (0.1–0.3 µm in diameter), and electron dense dark. These cells might represent a different stage of the spherulous cell 1. A third type, which seems like vacuolar cells (Figure 4 C), occurs with variable shapes, smaller size (5–8 µm in diameter), and containing a single round, dark dense granule (0.4–0.8 µm in diameter) within each vacuole (1–1.5 µm in diameter). By the shape and size of the granules, these cells likely correspond to the cell with inclusion 2 observed in the histological cross sections. Finally, a microgranular cell with membrane-bound inclusions with striated content, was observed once (Figure 4 D). A thick layer of collagen fibrils (Co) with loose bacteria surrounds the choanocyte chambers and long cytoplasmic projections could be seen in some choanocytes (Figure 4 E). One choanocyte with a basal nucleolated nucleus was observed (Figure 4 F). Remarks. The delicate and thin specimens of Vansoestia caribensis have been found in Bocas del Toro, Panama, since 2006; however, only the slow oxidation observed when specimens were placed into alcohol suggested an affinity to verongids. Due to the lack of a fiber skeleton, we initially affiliated this sponge to the genus Hexadella. Histological observations corroborated its ianthellid nature (large, sac-shaped choanocyte chambers), but its distinct identity and closest affinity to the known sequences of fiber-bearing ianthellid genera from the Western Tropical Pacific appeared after analyzing 18 S and 28 S ribosomal gene sequences (Redmond et al., 2013; Thacker et al., 2013). Its genetic distance from the only previously known fiber-less verongid genus, Hexadella, prompted the need to erect a new genus to classify this species. This biological record constitutes the first member of family Ianthellidae ever encountered in the Caribbean Sea. There is a striking similarity between V. caribensis gen nov. sp. nov. and the external appearance of Hexadella pruvoti Topsent, 1896 (Reveillaud et al., 2012), particularly with respect to the abundant subdermal canals converging in a wide oscule, and its yellowish coloration. However, 18 S and 28 S gene sequence analyses confirmed the very distinct nature of these two species. A cellularized cortex of variable thickness (10–200 µm thick) composed of amorphous collagen and various types of cells is present in V. cari bensis gen. nov. sp. nov. and forms an important morphological difference between these two genera, since Hexadella possesses a thinner cortex with a 1 µm thick cuticle. A well-developed cellularized cortex might represent a potential synapomorphy between Vansoestia gen. nov., Ianthella, and Anomoianthella (Bergquist, 1980, 1995; Bergquist and Kelly-Borges, 1995; Bergquist and Cook, 2002; present study). Indeed, Bergquist, (1995) and Bergquist and Kelly-Borges (1995) described a collagenous ectosome (70 to 300 µm thick) containing cells for all Ianthella species and a cellularized cuticle for Anomoianthella species (Bergquist, 1980). Together with the presence of a collagen-reinforced cortex combined with a cuticle, the high degree of reinforcement of the choanosome with collagen is also a characteristic shared by Vansoestia gen. nov., Ianthella and Anomoianthella. Some similarities among the spherulous cells of V. caribensis gen. nov. sp. nov., and other verongids were also noticed (Vacelet, 1967). The cells with striated membrane-bound bodies are very similar to cells observed in Aplysina aerophoba by Maldonado (2009). The dark granules found in cells of Vansoestia gen. nov. might represent glycogen granules (Maldonado, 2009), or they might contain brominated compounds (Thompson, 1986) like has been found for microgranular and spherulous cells of two different Aplysina species. The large diversity of cells with inclusions, and their similarities with species of Hexadella and other verongid genera invites continued research to understand the morphology and physiological functions of these cells and their products. Phylogenetic remarks. 18 S and 28 S sequences demonstrate that this fiber-less member of Ianthellidae is a sister group to the clade that includes Ianthella and Anomoianthella. (Redmond et al., 2013; Thacker et al., 2013). Figure 5 summarizes the current phylogenetic interpretation of the relationships among verongid genera based on the latest molecular, and morphologic studies of the group (Erwin and Thacker, 2007; Erpenbeck et al., 2012; Díaz et al., 2013; Redmond et al., 2013; Thacker et al., 2013). The two sister clades make up the subclass Myxospongiae, one containing the amended Verongida (after Redmond et al., 2013) and the other containing Chondrilla and Halisarca (Order Chondrillida sensu Redmond et al., 2013). All verongids are grouped in a strongly supported monophyletic clade (Figure 5, clade 1), which shares the presence of collagen fibrils forming bundles either in the cortex, in the mesohyl, or within fibers. Chondrosia (family Chondrosiidae) forms a wellsupported sister clade to all other verongids (Figure 5, clade 2), and is represented by sponges with extremely high collagen content, a thick (> 1 mm thick) “collagenous cortex”, and a fiber-less body. The rest of the verongids form a highly supported clade (Figure 5, clade 3), containing all taxa that produce brominated secondary metabolites and have abundant spherulous cells. Basal within this group, a highly supported clade (Figure 5, clade 4) contains all Hexadella species which share eurypylous choanocyte chambers, a thin cuticle (1–2 µm) and a very thin ectosome. The next clade (Figure 5, clade 5) is a moderately supported clade containing all non- Hexadella verongids. Within clade 5, two clades are distinguished: a moderately (85 %) supported clade (Figure 5, clade 6) containing Vansoestia gen. nov. (skeleton less) and the fiber bearing Pacific taxa of genera Ianthella and Anamoianthella, and a moderately to highly supported clade (Figure 5, clade 7) including all the taxa possessing diplodal choanocyte chambers. Within clade 7 (Figure 5), a clearly monophyletic group of sponges (clade 8) contains all Aplysina species, whereas a poorly supported clade (clade 9) contains at least six genera (Aiolochroia, Aplysinella, Porphyria, Pseudoceratina, Suberea, Verongula) and an undescribed genus from Moorea (Díaz et al., 2013). The Verongida taxa with eurypylous, sac-shaped choanocyte chambers are placed in two distinct clades (Figure 5, clades 4 and 6), demonstrating that this feature is paraphyletic within Verongida. Current studies suggest the classification of Verongida comprises four main clades: (1) a clear monophyletic group containing all Aplysina species studied, and representatives of all Aplysinellidae, and Pseudoceratiniidae genera; (2) a clade that contains Ianthella, Anomoianthella, and Vansoestia gen. nov., but excludes Hexadella, which should be defined by an amended family Ianthellidae; (3) a clade that presently contains only Hexadella and that should be erected as a new family; and (4) a clade containing the family Chondrosiidae sensu Redmond et al. (2013). We demonstrate here that the suprageneric classification of Verongida must be further revised in order to reflect our current knowledge of phylogenetic relationships among the genera of Myxospongiae. Considering the diagnostic characters that we have in hand, a thorough comparative review of the histological and ultrastructural features of representatives of each genus is definitely needed to improve the taxonomic diagnoses of these taxa.

International audience; A thin fiber-less sponge from Caribbean reefs (Bocas del Toro, Panama) with close genetic affinities (based on 18S and 28S nuclear ribosomal RNA gene sequences) to large fan-shaped fiber-bearing sponges (Ianthella and Anomoianthella) from the Indo-Pacific Ocean is here presented. We describe its overall external morphology, histological features, and ultrastructure. Its genetic distance from the only previously known fiber-less verongid genus, Hexadella, prompted the need to erect a new genus to classify this species. This novel species constitutes the first record for a member of the family Ianthellidae in the Caribbean. The characterization of the family Ianthellidae (sensu Cook and Bergquist, 2000) is here modified by: i) highlighting the cavernous nature of the choanosome, with many lacunae and channels reported for all genera included in the family; ii) extending the family distribution to the Caribbean; and iii) adding a fourth genus to the group of verongids with eurypylous chambers. The possession of a cellularized cortex (10-300 mu m in thickness) is here proposed as a potential synapomorphic character of the Ianthella-Anomoianthella-Vansoestia clade. The main issues regarding the suprageneric classification of verongids are discussed.

Genus Phorbas Duchassaing & Michelotti, 1864 Diagnosis: Thickly encrusting, massive or ramose sponges. Pores grouped in sieve-plates (areolae). Ectosomal skeleton with a crust of isochelae and diactinal spicules which form fans disposed at right angles and tangential to the surface; heavily spined acanthostyles core plumose or plumo-reticulate choanosomal tracts, or these may be replaced by smooth diactinal tornotes; echinating acanthostyles also heavily spined; microscleres are arcuate isochelae and sigmas, both of which may be absent. About 70 species. (From van Soest, 2002). Type species: Phorbas amaranthus Duchassaing & Michelotti, 1864 (by subsequent designation; de Laubenfels, 1936 a: 63)., Published as part of Vacelet, Jean & Perez, Thierry, 2008, Phorbas topsenti and Phorbas tailliezi (Demospongiae, Poecilosclerida), new names for the Mediterranean ' Phorbas paupertas ' and ' Phorbas coriaceus ', pp. 26-38 in Zootaxa 1873 on page 27, DOI: 10.5281/zenodo.184048, {"references":["van Soest, R. W. M. (2002) Family Hymedesmiidae Topsent, 1928. In Hooper, J. N. A. & van Soest, R. W. M. (eds), Systema Porifera: A Guide to the Classification of Sponges. Kluwer Academic / Plenum Publishers, New York, 575 - 593."]}

Phorbas topsenti sp. nov. (Figs. 1–4) Restricted synonymy. Anchinoe paupertas: Topsent, 1934: 25; Topsent, 1936: 43; Boury-Esnault, 1971: 318; Pansini, 1987: 166. Phorbas paupertas: Maldonado, 1993: 244; Carballo, 1994: 148. Holotype. MNHN DJV 113, Marseille, Anse des Cuivres near Station Marine d’Endoume, 43 ° 16 ' 47.46 "N, 5 ° 20 ' 57.22 "E, 7 m, 21 July 2004. Paratype 1. MNHN DJV 114, Marseille, Anse des Cuivres near Station Marine d’Endoume, 43 ° 16 ' 47.46 "N, 5 ° 20 ' 57.22 "E, 7 m, 21 July 2004. Paratype 2. MNHN DJV 115, Lebanon, Beirut harbour, 33 ° 54.36 ’N, 35 ° 30.98 ’E, 15 m, 9 July 2003. Paratype 3 MNHN DJV 116, Tunisia (Kerkennah Islands), 4 m, 16 December 1987. Other material examined. Numerous specimens from Marseille, Tunisia and Lebanon. Description. Thickly encrusting to massive (Fig. 1), thickness varying from a few millimeters to 25 mm, covering areas up to 100 cm ². Surface smooth, entirely covered by pore-sieves, 1.5–2 mm in diameter. Oscules scattered, 2–3 mm in diameter in preserved specimens. Consistency fleshy, rather soft. Colour deep red in live specimens, cream in alcohol. Skeleton. Dermal skeleton of dispersed strongyles, mostly tangential to the surface between the poresieves, and arranged in a dense palisade around the pore-sieves (Fig. 2 A). Choanosomal skeleton (Fig. 2 B) consisting of plumose ascending fibres, 80 µm in maximum thickness, with strongyles and acanthostyles I included in a feebly developed spongin, echinated by acanthostyles II and a few acanthostyles I. Isochelae present everywhere in the sponge, more numerous in the dermal membrane. Spicules (Fig. 3 A–F, Tables 1 and 2). Strongyles or subtylostrongyles, straight, frequently with slightly enlarged ovoid ends. Acanthostyles I, slightly curved, with a few short, generally blunt spines near the head. Acanthostyles II, straight, slightly conical, entirely spined, spines sharply pointed, curved toward the head along the shaft. Isochelae, arcuate, with shaft 3–3.3 µm in diameter, oval alae 8 µm long, central tooth wellformed, rudimentary fimbriae barely visible on some spicules. These spicules show rather low variations, according to the paratypes, to other specimens examined and to the literature (tables 1 and 2). The identification as Anchinoe paupertas by Pulitzer-Finali 1983 for specimens from the Italian coasts which are thinly encrusting and with no reported isochelae need to be checked. Histology and cytology (Fig. 4). Choanocyte chambers (Fig. 4 A, B) spherical, 23–26 µm in diameter, with small choanocytes. Two types of cells with inclusions present. Vacuolar cells (Fig. 4 C, D), numerous, generally ovoid with irregular outline, up to 14 x 6 µm, with a small, anucleate nucleus; cytoplasm more or less reduced between clear vacuoles with a sinuous outline. Vacuoles up to 3 µm in diameter, occupying most of the cell volume. Spherulous cells (Fig. 4 E), subspherical to elongate, up to 16 x 6 µm; nucleus with a central area containing a large crystal-like inclusion; spherules dense, homogeneous, 1–2 µm in diameter. Rather dense fascicles of collagen fibrils (Fig. 4 F) present in places. Two morphotypes of symbiotic bacteria present in the mesohyl although not abundant, rod-like bacteria (Fig. 4 F) and remarkable spiral-shaped bacteria (Fig. 4 G). Reproduction. A specimen from Lebanon (collected on 05/06/ 2000: 33 a) contained numerous embryos, spherical (150–200 µm in diameter) in the early stages and ovoid, up to 400 x 250 µm in the most mature stage where they contain thin strongyles (80–110 x 0.5 µm) dispersed without order, and incompletely developed isochelae. Spermatogenesis has been observed in a specimen collected in Marseille (30 /05/ 1984) (see De Vos et al. 1991). Symbiosis. The sponge is frequently associated with the amphipod Tritaeta gibbosa (Bate, 1862). Ecology. Common in well lit or semi-shaded areas, between 2 to 50 m. Distribution. Mediterranean (Tunisia, French, Italian and Spanish coasts, Gibraltar, Lebanon). The sponge is recorded from the Strait of Gibraltar (Carballo 1994), but the records as Anchinoe, Phorbas or Hymedesmia paupertas from outside the Mediterranean refer to Hymedesmia paupertas (for instance Cristobo et al. 1998 in Galicia). Etymology. The species is dedicated to Émile Topsent who first recognized this sponge in the Mediterranean. Remarks. This sponge was first described in the Mediterranean by Topsent (1934), who recorded it from Tunisia and from the Mediterranean French coasts. Topsent wrongly identified the sponge as Anchinoe (now Phorbas) paupertas, described from the north European coasts by Bowerbank (1866) as Hymeniacidon paupertas, which at that time was poorly defined and which is a Hymedesmia. Recent revisions have shown that Hymedesmia paupertas (Bowerbank) is a thinly encrusting, blue or green sponge from the North East Atlantic, with an hymedesmioid skeleton, which is clearly different from the red Mediterranean sponge (van Soest et al. 2000). We thus propose a new name for the Mediterranean sponge, which has often been recorded as Phorbas paupertas. The ‘true’ Hymedesmia paupertas has apparently not been observed in the Mediterranean. Phorbas topsenti sp.nov. closely resembles by its field characters two sponges of the same family, Phorbas fictitius (Bowerbank, 1866) and Hamigera hamigera (Schmidt, 1862). The three sponges are clearly distinct by their spiculation, the major differences being the presence of tornotes instead of strongyles in P. fictitius, and the absence of true acanthostyles in H. hamigera (Figs. 5, 6). However, they are extremely difficult to distinguish in the field. Phorbas fictitius appears to have a more variable colour, varying from deep red to grey and pale orange pink in the NE Atlantic (van Soest et al. 2000). However, in the NW Mediterranean, P. fictitius appears always as red, possibly a little more vivid than P. topsenti sp.nov. The three species have the same ecological distribution, but are generally not found together in the same area. In our experience on the French coasts of the NW Mediterranean, the species most commonly found in the Marseille area is P. topsenti sp.nov., whereas P. fictitius is more common in Port-Cros and H. hamigera in Banyuls. The present cytological study shows that P. topsenti sp.nov. and H. hamigera are closely related, having similar vacuolar and spherulous cells, including crystal-like nuclear inclusion, and similar spiral-shaped bacteria (Boury-Esnault 1972, 1976). These bacteria have been rarely observed in other sponges, but resemble to a greater or lesser extent those described in Grantia compressa (Vacelet & Donadey 1977), in Clathrina cerebrum (Burlando et al. 1988), and in Halisarca dujardini (Ereskovsky et al. 2005), which have no relationship with these poecilosclerids.

Vacelet, Jean, Borchiellini, Carole, Perez, Thierry, Bultel-Poncé, Valérie, Brouard, Jean-Paul, Guyot, Michèle (2000): Morphological, chemical and biochemical characterization of a new species of sponge without skeleton (Porifera, Demospongiae) from the Mediterranean Sea. Zoosystema 22 (2): 313-326, DOI: http://doi.org/10.5281/zenodo.5399304, {"references":["TYPE SPECIES. - Thymosiopsis cuticulatus Vacelet & Perez, 1998 by monotypy.","TYPE MATERIAL. - Holotype: La Ciotat. Northwestern Mediterranean, near opening of 3PP cave, 17 m, 26.I.1998, one fragment (MNHN D JV 64). Paratype: same locality, 22.X.1998 (MNHN D JV 65)."]}