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The study of Avilés Canyon System has been done within the framework of the EU-funded Nature + LIFE INDEMARES (07/NAT/E/ 000732) and INTEMARES (LIFE15 IPE ES 012) projects; ST received funding from the grant PID2020-117115GA-100 funded by MCIN/AEI/10.13039/50110001103 (...), Ríos, P., Altuna, Á., Frutos, I., Manjón-Cabeza, E., García-Guillén, L., Macías-Ramírez, A., Ibarrola, T.P., Gofas, S., Taboada, S., Souto, J., Álvarez, F., Saiz-Salinas, J.I., Cárdenas, P., Rodríguez-Cabello, C., Lourido, A., Boza, C., Rodríguez-Basalo, A., Prado, E., Abad-Uribarren, A., Parra, S., Sánchez, F., Cristobo, J.

North Atlantic specimens attributed to the genus Stilipes were first reported by Lagardère in 1977, and subsequently sampled during different research programmes on suprabenthic communities from the southern Bay of Biscay and the Galicia Bank. Their morphological study showed that they belong to a new species to science, discriminated from the four known species S. distinctus Holmes1908; S. lacteus (K.H. Barnard, 1931); S. sanguineus (Hurley, 1954) and S. macquarensis Berge 2003. The new species was sampled in the near-bottom water layer with several multinet suprabenthic sledges. Within its known distributional area, Stilipes lagarderei sp. nov. is living between 462 and 1060 m depth on muddy bottoms in the canyons and on fine and medium sands on the seamounts. This upper bathyal species is very rare with a maximum abundance registered on the Galicia Bank (12.9 ind./100 m2). Considered to be a mesopelagic species, as for its congeners, the data herein presented demonstrate that Stilipes lagarderei sp. nov., colonizes the near-bottom environment, thus exhibiting a suprabenthic behavior. An identification key to the known Stilipes species is provided. Ecological notes and biological comments of the new species are also presented.

The present paper provides data of the world-wide distribution, abundance and diversity of the rare deep-sea munnopsid genus, Acanthocope Beddard, 1885 and presents an identification key to the 18 known species of Acanthocope. Two new species, Acanthocope puertoricana sp. nov. from the tropical abyssal area near the Puerto Rico Trench and Acanthocope galaica sp. nov. from the Galicia Bank, Northeastern Atlantic are described. Additionally, Acanthocope annulatus Menzies, 1962 and Acanthocope eleganta Malyutina and Brandt, 2004 have been collected in the Puerto Rico Trench area, whereas Acanthocope galatheae Wolff, 1962 were collected along a latitudinal transect crossing the tropical abyssal North Atlantic during the Vema-TRANSIT expedition. A. puertoricana is most similar to A. carinata Chardy, 1972 from the Northwestern Atlantic and differs from the latter by: a more slender body; a broader head; a more slender and shorter lateral projections of the pleotelson; the presence of ventral spines on natasome; and a longer uropod. A. galaica sp. nov. is most similar to A. spinicauda Beddard, 1885 and differs from the latter by having a more elongate pleotelson with almost straight lateral margins between lateral spines, whereas the margins are more convex in A. spinicauda. Pereopods 5 and 6 of A. galaica have broader carpi than in A. spinicauda.

We analyzed composition and variations in benthic macrofaunal communities along a transect of the entire length of the Vema-Fracture Zone on board of RV Sonne (SO-237) between December 2014 and January 2015 in order to test whether the Mid-Atlantic Ridge serves as a barrier limiting benthic taxon distribution in the abyssal basins on both sides of the ridge or whether the fracture zone permits the migration of species between the western and eastern abyssal Atlantic basins. The Puerto Rico Trench, much deeper than the surrounding abyssal West Atlantic, was sampled to determine whether the biodiversity of its hadal macrofauna differs from that of the abyssal Atlantic. The composition of the macrofauna from the epibenthic sledge catches yielded a total of 21,332 invertebrates. Crustacea occurred most frequently (59%) with 12,538 individuals followed by Annelida (mostly Polychaeta) (26%) with 5491 individuals, Mollusca (7%) with 1458 individuals, Echinodermata (4%) with 778 individuals, Nematoda (2%) with 502 individuals and Chaetognatha (1%) with 152 and Porifera (1%) with 131 individuals. All other taxa occurred with overall less than ten individuals (Hemichordata, Phoronida, Priapulida, Brachiopoda, invertebrate Chordata, Echiurida, Foraminifera (here refereed to macrofaunal Komokiacea only), Chelicerata, Platyhelminthes). Within the Crustacea, Peracarida (62.6%) with 7848 individuals and Copepoda (36.1%) with 44,526 individuals were the most abundant taxa. Along the abyssal Vema-Fracture Zone macrofaunal abundances (ind./1000 m 2 ) were generally higher on the eastern side, while the highest normalized abundance value was reported in the Puerto Rico Trench at abyssal station 14-1 2313 individuals/1000 m 2 . The lowest abundance was reported at station 11-4 with 120 ind./1000 m 2 located at the western side of the Vema-Fracture Zone. The number of major macrofaunal taxa (phylum, class) ranged between five (stations 12-5, 13-4 and 13-5 at hadal depths in the Puerto Rico Trench) and 14 (station 9-8) in the western abyssal basin of the Vema-Fracture Zone. Differences are seen in the distribution of Porifera at macrofaunal level between eastern and western sides of the Vema-Fracture Zone. Macrofaunal composition of the study area is compared with data from other expeditions in the Atlantic and the northwest Pacific Ocean.

In the Capbreton area, suprabenthic assemblages were sampled with a sledge towed over the bottom, at different sites located within the upper part of a ‘gouf-type’ canyon (8 hauls between 642 m and 797 m, on the axis of the thalweg or on flat perched flank terraces such as site K), on the northern adjacent open slope (2 hauls between 500 and 567 m) and on the northern adjacent shelf margin (2 hauls between 151 m and 158 m). A multivariate analysis carried on the faunal data discriminated different assemblages in this area: a near-canyon shelf assemblage (55 species, mainly amphipods and decapods; 3496 ind./100 m 2 , 40% mysids; dominant species: Nyctiphanes couchii, Leptomysis gracilis, Weswoodilla rectirostris, Anchialina agilis, Scopelocheirus hopei and Philocheras bispinosus ); an open slope assemblage (111 species, mainly amphipods and isopods; 249 ind./100 m 2 , 36% amphipods; dominant species: Disconectes phalangium, Munnopsurus atlanticus and Boreomysis arctica ); a canyon E assemblage (129 species, mainly amphipods, mysids and cumaceans; 1172 ind./100 m 2 , 58% amphipods; dominant species: Melphidippa sp. B, Chelator insignis ); a canyon E’ assemblage (107 species, mainly amphipods and mysids; 507 ind./100 m 2 , 73% amphipods; dominant species: Cleonardopsis carinata, Bonnierella abyssorum, Rhachotropis caeca and Arcturopsis giardi ); and a temporary canyon assemblage at site K (34 species, mainly amphipods and mysids; 899 ind./100 m 2 , 85% amphipods; dominant species: Tmetomyx similis, Caeconyx caeculus, Nebalia sp. A and Cleonardopsis carinata ). Site K was sampled only four months after a turbidity event, detected on sediment cores (18 cm thick Bouma sequence) taken during the same cruise and triggered by the violent storm (‘ouragan Martin’, wind up to 200 km/h) which affected the French Atlantic coast on 27 December 1999. The corresponding suprabenthic assemblage showed evidence of deep structural changes after this catastrophic event, characterized by relative low values of species richness and diversity indices and by the exceptional dominance of opportunistic pioneer colonizers such as the scavenger Tmetonyx similis (61% of total density). Partial assemblage recovery was noticed 18 months after the turbidite deposition, attested by higher values of structural indices and by the inclusion of the corresponding sample within the climax canyon assemblage cluster.

13 pages, 9 figures, 4 tables, 1 appendix, Crustacean suprabenthic abundance, community structure, α-diversity (both taxonomic and trophic) and β-diversity were studied along a West-East gradient of oligotrophy in the deep Mediterranean Sea. The assemblages were sampled with a suprabenthic sledge in three regions (western, central and eastern basins) at three water depths (1200, 2000 and 3000 m) in May-June 2009. Environmental data were obtained at each sampling location including sediment properties, oceanographic variables near the seafloor and in the water column, and proxies of epipelagic productivity at the surface. Our results, concerning the crustacean component of the suprabenthos, showed complex trends in community structure and biodiversity across different spatial scales (longitudinal, bathymetric, and near-bottom distribution). A decrease in the number of species and abundance, accompanied by changes in the trophic structure of the assemblages were observed from West to East. In the eastern region the assemblages were impoverished in number of trophic guilds and trophic diversity. The West-East oligotrophic gradient was identified as the main driver in community structure as shown by the significant correlation with trophic environmental variables. Differences in community structure across regions were more marked at greater depths, while at the shallower sites assemblages were more similar. Within each basin, abundance, number of species and number of trophic groups decreased with depth, showing high turnover rates between 1200 and 2000 m depths. The small-scale (0–150 cm) vertical distribution of the suprabenthos was interpreted in relation to the species’ functional traits (e.g. swimming activity, migratory behaviour, bottom dependence, feeding habits). Bottom-dependent and more mobile components of the suprabenthos were apparently responding differently to the various environmental challenges imposed by the large-scale longitudinal and bathymetric gradients. We propose that the bathyal suprabenthos in the Mediterranean Sea may be essentially modulated by environmental sorting, but while the more mobile faunal component has more efficient dispersal mechanisms, the bottom-dependent component may be affected by limited dispersal. However, this empirical interpretation has still to be proved given the important caveats of our study (e.g. typically low densities of the Mediterranean bathyal suprabenthos; limited number of samples; difficulties in standardization inherent to suprabenthic sampling operations in the deep sea), This work was funded through the BIOFUN project (CTM2007-28739-E) within the framework of the EuroCores EuroDEEP programme (European Science Foundation). This study was partially funded by Fundação para a Ciência e Tecnologia (FCT) under the projects PEst-C/MAR/LA0017/2013 and UID/AMB/50017/2013. The first author was funded by a PhD grant from FCT (SFRH/BD/69450/2010).

A new family of paratanaoidean Tanaidacea – Paranarthrurellidae fam. nov. – is erected to accommodate two genera without family classification (Paratanaoidea incertae sedis), namely Armatognathia Kudinova-Pasternak, 1987 and Paranarthrurella Lang, 1971. Seven new species of Paranarthrurella and two of Armatognathia are described from material taken in different deep-sea areas of the Atlantic and Pacific oceans. The type species of Paranarthrurella — P. caudata (Kudinova-Pasternak, 1965) — is redescribed based on the paratype. The genus Cheliasetosatanais Larsen and Araújo-Silva, 2014 originally classified within Colletteidae is synonymised with Paranarthrurella, and Arthrura shiinoi Kudinova-Pasternak, 1973 is transferred to Armatognathia. Amended diagnoses of Armatognathia and Paranarthrurella genera are given. Choosing characters for distinguishing and defining both genera was supported by Principal Component Analysis. Designation of the new family is supported by molecular phylogenetic analysis of COI and 18S datasets. The distribution of all species currently included in the new family was visualised and their bathymetric distribution analysed.

International audience; A new species ascribed to a new genus of Eusiridae, Dorotea papuana gen. nov., sp. nov. is described from bathyal bottoms of the Solomon Sea (Papua New Guinea). Closely related to the genus Cleonardo, this new genus can be distinguished from most other known eusirid genera by the presence of a telson distally cleft and distinctly bilobate, of a distal spiniform process on uropods 1 peduncle and of a simple, stout and medium length dactylus on pereopods 5-7. The combination of all these characters can be considered relevant for the affiliation of this species to a new genus within Eusiridae. Due to its very close morphological affinity to Dorotea gen. nov., the bathyal sub-Antarctic species Eusiroides aberrantis Bellan-Santini & Ledoyer, 1987 cannot be maintained in the family Pontogeneiidae and it should be transferred to the family Eusiridae.

Source at https://doi.org/10.3897/zookeys.731.19854. Amphipod crustaceans were collected at all 55 stations sampled with an epibenthic sledge during two IceAGE expeditions (Icelandic marine Animals: Genetics and Ecology) in 2011 and 2013. In total, 34 amphipod families and three superfamilies were recorded in the samples. Distribution maps are presented for each taxon along with a summary of the regional taxonomy for the group. Statistical analyses based on presence/absence data revealed a pattern of family distributions that correlated with sampling depth. Clustering according to the geographic location of the stations (northernmost North Atlantic Sea and Arctic Ocean) can also be observed. IceAGE data for the Amphilochidae and Oedicerotidae were analysed on species level; in case of the Amphilochidae they were compared to the findings from a previous Icelandic benthic survey, BIOICE (Benthic Invertebrates of Icelandic waters), which also identified a high abundance of amphipod fauna.

Special issue Changing Ecosystems in the Bay of Biscay: Natural and Anthropogenic Effects.-- 12 pages, 7 figures, 4 tables, 1 annex, Galicia Bank is a deep seamount included as Site of Community Importance (SCI) in the Spanish Natura 2000 Network proposal. In the present study, epibenthic assemblages of sedimentary habitats have been described, together with the main environmental factor explaining species and communities distribution. Five epibenthic assemblages have been identified. Depth was the main factor explaining assemblage distribution, and the role of sediment type, water masses, and coral framework presence is also discussed. Three assemblages are located in the summit: the shallowest one (730–770 m), in the boundary between Eastern North Atlantic Central Water (ENACW) and Mediterranean Overflow Water (MOW) water masses is typified by ophiuroids and characterized by medium sands. The second assemblage (770–800 m) typified by the bivalve Limopsis minuta and the solitary coral Flabellum chunii correspond with medium sands and MOW core; and the third typified by the presence of cold-water coral communities dominated by Lophelia pertusa and Madrepora oculata, also on the MOW influence. In the border of the summit, in the bank break, an assemblage located in the range 1000–1200 m is dominated by the urchin Cidaris cidaris and the sponge Thenea muricata. In the flat flanks around the bank, the deepest assemblage (1400–1800 m) is dominated by the holothurian Benthogone rosea, in a depth range dominated by the Labrador water (LSW) and in fine sands with highest contents of organic matter. Most of species appeared in a depth range smaller than 25% of total depth range sampled and in < 10% of samples. Differential preference of species is evident in the different trophic guilds, with a higher dominance of filter-feeders in the summit and of deposit-feeders in the deepest assemblage, and have clear links with nutrient dynamics in the bank, This study was financed by the EC contract INDEMARES-LIFE (07/NAT/E/000732)

The bathyal suprabenthic fauna of the Kostarrenkala area (Capbreton Canyon, SE Bay of Biscay) was sampled during daytime at eight stations located on a bathymetric transect between 175 and 1000 m depth using a multinet suprabenthic sled. Two hundred and five suprabenthic taxa were recorded in this area, mainly amphipods, cumaceans, isopods and mysids. Total abundances ranged from 752 to 2640 ind./100 m 2 , showing a decreasing trend with depth. Diversity values ( H ′) ranged between 3.83 and 5.72, increasing significantly with depth. Multivariate analysis of abundance data discriminated three assemblages according to depth: shelf break (72 sp., 1924 ind./100 m 2 ), upper slope (93 sp., 1485 ind./100 m 2 ) and mid slope (135 sp., 857 ind./100 m 2 ) assemblages. Each assemblage was characterised by a distinct dominant species: the shelf amphipod Westwoodilla caecula at the shelf break, the isopod Munnopsurus atlanticus on muddy sand bottoms of the upper bathyal, and the amphipod Rhachotropis gracilis on mid-slope muddy bottoms below the mud line. Such a structure of bathyal assemblages seems to be generalised for the whole margin of the Bay of Biscay.

The aim of this study was to investigate the diversity and distribution of the asellote isopod family Ischnomesidae in the hadal and abyssal of the Kuril-Kamchatka Trench (KKT) and adjacent Sea of Okhotsk and the neighboring northwest Pacific Basin. Ischnomesids were sampled during two expeditions (SokhoBio & KuramBio II) in depths between 3299 and 9584 m. Subsequent to morphological identifications, mitochondrial COI was successfully sequenced for 208 of the 298 sampled specimens. Based on two computational approaches (ABGD and GMYC) 24–45 putative species (lineages) could be delimited. The initially 21 defined morphospecies matched poorly with these COI lineages, in particularly females and juveniles were differently assigned. Fortimesus Kavanagh and Wilson, 2007 was found to be the most abundant and diverse genus, in particular in the hadal. The hadal of the KKT had a higher species diversity (6–9 species) than the adjacent Sea of Okhotsk (1 species), but lower diversity than the abyssal northwest Pacific Basin (15–24 species). Most species were restricted to a single studied area, wider distributions of ~300 km were mainly observed for hadal species within the KKT and only to a lesser degree for abyssal species. Species distributions across the KKT were rare and again predominately observed for hadal species. The abyssal species were either restricted to one side of the KKT or the genetic distances between populations on the opposite sides of the KKT were very high. This implies that the KKT serves as an isolation barrier for poorly dispersing benthic species like the herein studied Ischnomesidae.

During joint Russian-German SokhoBio expedition held in 2015, the deepest area of the Sea of Okhotsk (Kuril Basin), the Bussol Strait and the western abyssal slope of the Kuril-Kamchatka Trench were investigated using camera epibenthic sledge. In total, 19 stations ranged between 1696 and 4798 m depth were sampled. The amphipods constituted 10% of all macroinvertebrates and one fourth of all Peracarida. The identification of families resulted in 32 taxa of which two (Liljeborgiidae and Valettiopsidae) were recorded for the first time from the Sea of Okhotsk. The most abundant group was Corophiida (17.4%), followed by the Oedicerotidae (15.8%), the Phoxocephalidae (12.3%), and the Eusiridae (11.7%). A multivariate analysis carried on the amphipod family abundance data (three stations excluded), discriminated four different assemblages in the studied area: a Bussol Strait assemblage (group A, two stations, 2327–2333 m) dominated by Corophiida group; a Kuril Basin assemblage (group B, 11 stations, 3210–3366 m) characterized by Oedicerotidae and Phoxocephalidae; and two assemblages in the Kuril-Kamchatka Trench area: a single station (group C, 4681 m) dominated by Phoxocephalidae and two grouped stations (group D, 3371–4798 m) characterized by Lysianassoidea. The effect of environmental variables on amphipod taxocenosis was also discussed.

Special issue Advances in deep-sea biology: biodiversity, ecosystem functioning and conservation.-- 13 pages, 6 figures, 6 tables, Trophic interactions in the deep-sea fish community of the Galicia Bank seamount (NE Atlantic) were inferred by using stomach contents analyses (SCA) and stable isotope analyses (SIA) of 27 fish species and their main prey items. Samples were collected during three surveys performed in 2009, 2010 and 2011 between 625 and 1800 m depth. Three main trophic guilds were determined using SCA data: pelagic, benthopelagic and benthic feeders, respectively. Vertically migrating macrozooplankton and meso-bathypelagic shrimps were identified to play a key role as pelagic prey for the deep sea fish community of the Galicia Bank. Habitat overlap was hardly detected; as a matter of fact, when species coexisted most of them evidenced a low dietary overlap, indicating a high degree of resource partitioning. A high potential competition, however, was observed among benthopelagic feeders, i.e.: Etmopterus spinax, Hoplostethus mediterraneus and Epigonus telescopus. A significant correlation was found between δN and δC for all the analysed species. When calculating Trophic Levels (TLs) for the main fish species, using both the SCA and SIA approaches, some discrepancies arose: TLs calculated from SIA were significantly higher than those obtained from SCA, probably indicating a higher consumption of benthic-suprabenthic prey in the previous months. During the summer, food web functioning in the Galicia Bank was more influenced by the assemblages dwelling in the water column than by deep-sea benthos, which was rather scarce in the summer samples. These discrepancies demonstrate the importance of using both approaches, SCA (snapshot of diet) and SIA (assimilated food in previous months), when attempting trophic studies, if an overview of food web dynamics in different compartments of the ecosystem is to be obtained, The present work was funded by the LIFE+INDEMARES project (EC contract INDEMARES-LIFE, 07/NAT/E/000732)

A new bathyal leucothoid amphipod, Leucothoe cathalaa sp. nov., is described and illustrated based on specimens collected at the Le Danois Bank (‘El Cachucho’ Marine Protected Area), southern Bay of Biscay. This species can be distinguished from the other species of the genus Leucothoe by the hardly visible eyes (translucent ocelli, in preserved specimens); antenna 1 with minute accessory flagellum; coxae 1–3 with 2 serrations on posterodistal margin; epimeron 3 posterodistal corner produced, bifid, with one seta between blunt lobes and telson apex pointed without accessory teeth. In live specimens, the eyes are easily visible, each represented as a rounded whitish-pigmented spot. The new species has been found living on fine sandy soft-bottoms between 486 and 574 m depth at the top of the bank. An identification key to the deep Atlantic European species of Leucothoe is provided, as well as ecological and biological comments.

17 páginas, 8 figuras, 5 tablas, 1 apéndice con 3 tablas., Blanes Canyon and its adjacent margin are important fishery areas (mainly by bottom trawling) located in a highly energetic oceanographic setting in the NW Mediterranean Sea. Here we assess the spatial and temporal variability in abundance, diversity and community structure of the suprabenthic peracarid assemblages in this region and examine this variability in relation to the natural and anthropogenic (trawling fisheries) disturbance regimes. The sampling was conducted between March 2003 and May 2004 in three main fishing grounds, the canyon head (average depth: 490 m), the canyon wall (average depth: 550 m) and the eastern adjacent slope (average depth: 820 m), as well as in two non-exploited areas in the western (at 900 m depth) and eastern (at 1500 m depth) slope near the canyon mouth. A total of 138 species were identified, with amphipods being the most speciose and abundant group, followed by mysids in terms of abundance. Our results show high spatial and temporal variability in suprabenthic assemblages. Densities were higher in the canyon head and western slope, which appear to be the preferential routes for water masses and particle fluxes in months of flood events, and other energetic processes. In the canyon head, where periodic erosion processes are more active, low diversity, high dominance and higher turnover (β-diversity) were observed, apparently coupled with significant temporal fluctuations in the densities of the highly motile component of suprabenthos (mysids, predatory and scavenging amphipods). In the sedimentary more stable eastern slope, high diversity values were observed, accompanied by a higher relative contribution of the less motile groups (i.e. amphipods, most isopods, cumaceans). These groups have a closer interaction with the sediment where they exploit different food sources and are more susceptible to physical disturbance. Temporal variability in their diversity may be related to changes in food quality rather than quantity. In the canyon wall, temporal fluctuations in diversity indices were only revealed in relation to the overall higher and more continued fishing pressure observed in the canyon wall fishing ground (Cara Norte/Sot site). Here, species richness and abundance declined with increasing fishing pressure but the lowest trophic and taxonomic diversities were observed under intermediate levels of disturbance. These findings underline (i) the differences between relatively low and highly motile taxa in terms of response to disturbance events; (ii) the differences between assemblages subjected to different levels of natural disturbance and trawling pressure, which modify the common bathymetric patterns of abundance and diversity often described from continental margins., This study was conducted within the framework of the project RECSII (REN02/04556/C02/ MAR) by the Spanish Science and Innovation Agency. The study is a contribution of D. Martin to the Consolidated Research Group 2014SGR120 of the Generalitat de Catalunya. The first author was supported by Fundação para a Ciência e Tecnologia: SFRH/BPD/ 21459/2005. C. Romano received funding from the People Programme (Marie Curie Action) of the European Union's Seventh Framework Programme (FP7/2007-2013) under REA grant agreement N. PIOF-GA-2013-628146. This study was partially funded by Fundação para a Ciência e Tecnologia (FCT) under the projects PEst-C/MAR/LA0017/2013 and UID/AMB/50017/2013.

Two years after the Prestige oil spill (POS) an assessment of the effects on benthic fauna was carried out using the data obtained in five multidisciplinary surveys. Otter trawl, beam trawl, suprabenthic sled and box corer were used to study the main benthic compartments, along eight transects perpendicular to the coastline. Beam trawl was also employed to quantify the amount of tar aggregates on the continental shelf. No significant correlations between tar aggregates and species richness, biomass and diversity of benthic communities were found. This result was corroborated when the role of depth, season, latitude and sediment characteristics was examined by canonical ordination, in which POS-related variables had low influence on spatial distribution patterns. Depth and sediment grain diameter profoundly influence epibenthic communities. Sediment organic content is a third key variable for the infaunal, suprabenthic and lower-sized epibenthic communities, but not for the larger epibenthic communities. Nevertheless, a decrease in the densities of several epibenthic indicators was detected the first year after spill, followed by a noteworthy recovery in 2004. Non-macroscopic toxicity and some oceanographic agents are suggested as possible causes of these shifts.

A new species of Ischnomesidae (Crustacea: Isopoda: Asellota), Ischnomesus harrietae sp. nov. is described from the southern Bay of Biscay. This new species is distinctive due to the presence of numerous pedestal setae arranged in longitudinal rows on pereonite 5. Because of this morphological peculiarity, it can be easily distinguished from the four other Ischnomesus species previously reported from bathyal/abyssal bottoms of the European continental margin. Within its known distributional area, the new species inhabits sandy and muddy bottoms between 619 and 1099 m, with a maximum abundance of 41.8 individuals per 100 m2 recorded at approximately 700 m on the Arcachon Plateau. Another new species is also reported, Ischnomesus sp.1, represented by one specimen only and briefly described. An identification key to European species of Ischnomesus is provided.

Special issue Oceanography of the Bay of Biscay.-- 14 pages, 6 figures, 6 tables, The Galicia Bank (NE Atlantic, 42°67′N–11°74′W) is an isolated seamount, near NW Spain, a complex geomorphological and sedimentary structure that receives influences from contrasting water masses of both northern and southern origins. Within the project INDEMARES, three cruises were performed on the bank in 2009 (Ecomarg0709), 2010 (BanGal0810) and 2011 (BanGal0811) all in July–August. Decapods and other macrobenthic crustaceans (eucarids and peracarids) were collected with different sampling systems, mainly beam trawls (BT, 10 mm of mesh size at codend) and a GOC73 otter trawl (20 mm mesh size). Sixty-seven species of decapod crustaceans, 6 euphausiids, 19 peracarids and 1 ostracod were collected at depths between 744 and 1808 m. We found two new species, one a member of the Chirostylidae, Uroptychus cartesi Baba & Macpherson, 2012, the other of the Petalophthalmidae (Mysida) Petalophthalmus sp. A, in addition to a number of new biogeographic species records for European or Iberian waters. An analysis of assemblages showed a generalized species renewal with depth, with different assemblages between 744 and ca. 1400 m (the seamount top assemblage, STA) and between ca. 1500 and 1800 m (the deep-slope assemblage over seamount flanks, DSA). These were respectively associated with Mediterranean outflow waters (MOW) and with Labrador Sea Water (LSW). Another significant factor separating different assemblages over the Galician Bank was the co-occurrence of corals (both colonies of hard corals such as Lophelia pertusa and Madrepora oculata and/or gorgonians) in hauls. Munidopsids (Munidopsis spp.), chirostylids (Uroptychus spp.), and the homolodromiid Dicranodromia mahieuxii formed a part of this coral-associated assemblage. Dominant species at the STA were the pandalid Plesionika martia (a shrimp of subtropical-southern distribution) and the crabs Bathynectes maravigna and Polybius henslowii, whereas dominant species in the DSA were of northern origin, the lithodid Neolithodes grimaldii and the crangonid Glyphocrangon longiristris, likely associated with LSW. The diversity (H and J) of small crustaceans (collected with BT) seemed to be controlled by the phytoplankton blooms (satellite Chl a data) over bank surface 3 months before the samplings, both at the top (Spearman r=0.57, p=0.03) and on the flanks (r=0.74, p=0.02) of Galicia Bank, while no significant relationships with Chl a were found for the larger decapods collected with GOC73, on average they feed at the higher trophic levels than those collected with BT

The trophodynamics of pelagic and benthic animals of the North Sea, North Atlantic shelf, were assessed using stable isotope analysis (SIA) of natural abundance carbon and nitrogen isotopes, lipid fingerprinting and compound-specific SIA (CSIA) of phospholipid-derived fatty acids (PLFAs). Zooplankton (z), epi- and supra-benthic macrofauna were collected in the Southern Bight, at the Oyster Grounds and at North Dogger, 111 km north of the Dogger Bank. The study included 22 taxonomic groups with particular reference to Mollusca (Bivalvia and Gastropoda) and Crustacea. Primary consumers (Bivalvia) were overall most N-15 enriched in the southern North Sea (6.1aEuro degrees) and more depleted in the Oyster Grounds (5.5aEuro degrees) and at North Dogger (2.8aEuro degrees) demonstrating differences in isotopic baselines for bivalve fauna between the study sites. Higher trophic levels also followed this trend. Over an annual cycle, consumers tended to exhibit N-15 depletion during spring followed by N-15 enriched signatures in autumn and winter. The observed seasonal changes of delta N-15 were more pronounced for suspension feeders and deposit feeders (dfs) than for filter feeders (ffs). The position of animals in plots of delta C-13 and delta N-15 largely concurred with the expected position according to literature-based functional feeding groups. PLFA fingerprints of groups such as z were distinct from benthic groups, e.g. benthic ffs and dfs, and predatory macrobenthos. delta C-13(PLFA) signatures indicated similarities in C-13 moiety sources that constituted delta C-13(PLFA). Although functional groups of pelagic zooplankton and (supra-) benthic animals represented phylogenetically distinct consumer groups, delta C-13(PLFA) demonstrated that both groups were supported by pelagic primary production and relied on the same macronutrients such as PLFAs. Errors related to the static categorization of small invertebrates into fixed trophic positions defined by phylogenetic groupings rather than by functional feeding groups, and information on seasonal trophodynamic variability, may have implications for the reliability of numerical marine ecosystem models.

A new species of the genus Politolana (Crustacea, Isopoda, Cirolanidae) is described, based on specimens collected from the Le Danois Bank (‘El Cachucho’ fishing ground), southern Bay of Biscay, northeastern Atlantic Ocean. Politolana sanchezi sp. nov. can be distinguished from P. microphthalma (the only Politolana species recorded in boreal European waters) by larger eyes, presence of chromatophores on pereon and pleon, antennae reaching to the middle of the second pereonite, lateral margin of the frontal ridge dividing eyes, superior meral lobe of pereopod 1 reaching midpoint of the propodus, distal end of uropodal endopod subacute and pleotelson apex broadly convex with small medial point. An identification key to the world species of Politolana is presented. The new species has been found living on muddy-fine sandy bottoms of the southern Bay of Biscay and western Galicia, between 480 and 791 m depth. According to the present findings, it belongs to the benthic scavenger guild recognized on continental slopes. Its scavenging and bioturbating behaviour at the sediment-water interface are described from in situ trophic experiments with a fish-baited trap combined with a time-lapse recording camera.

25 pages, 8 figures, 3 tables, The feeding habits of birdbeak dogfish Deania calcea, velvet belly lantern shark Etmopterus spinax and blackmouth catshark Galeus melastomus at Le Danois Bank, Cantabrian Sea, south Bay of Biscay were studied in relation to their bathymetric distribution. Deep-sea sharks were collected during two multidisciplinary surveys carried out in October 2003 and April 2004 at the Le Danois Bank. Two different habitats were defined: (1) the top of the bank, ranging from 454 to 642 m depth and covered by fine-sand sediments with a low percentage of organic matter, and (2) the inner basin located between the bank and the Cantabrian Sea’s continental shelf, at depths of 810–1048 m, which was characterized by a high proportion of silt and organic matter. Deania calcea was not present at the top of the bank but was abundant below 642 m, while E. spinax was abundant in the shallower top of the bank but was not found in the deeper inner basin. There was almost no bathymetric overlap between these two deep-sea shark species. Galeus melastomus was found over the whole depth range. There seemed to be an ontogenetic segregation with depth for this species, however, since 80% of the specimens collected at the top of the bank were, This study was partially funded by the Spanish Ministry of Science and Technology and included in the ECOMARG Project (REN2002-00916/MAR). The study of sedimentary characteristics was performed by the benthic team of the A Coruña Oceanographic Centre (IEO)

Spatial distribution patterns of epibenthic communities on the Galician continental shelf were studied using multivariate methods. Data came from 5 surveys carried out in 2002, 2003 and 2004. Beam trawls and otter trawls were used to study epibenthic communities along 8 transects perpendicular to the coastline. The role of depth, season, latitude and sediment characteristics was examined. Seven habitats were described according to bathymetry and sediment characteristics. There were weak linear relationships between environmental variables and species richness, biomass and species diversity. However, the canonical analysis showed that depth and sediment characteristics greatly influence smaller epibenthic communities sampled by beam trawl. Six assemblages were obtained for beam trawls: inner shelf mud, very fine sands, and fine sands, middle shelf sands, and outer shelf very fine sands, and fine sands. Five assemblages were identified for larger-sized and swimming epibenthos sampled with otter trawls. These assemblages were also determined according to depth and sediment type but sediment characteristics were less important. Otter trawl assemblages were the same as the beam trawl ones, except for on the outer shelf where no differences between sediment type were detected. For both gears, inner and outer shelf assemblages displayed a higher biotic variability than the middle shelf, as a consequence of a higher environmental heterogeneity. Typifying species were mainly eurytopic in the middle shelf, whereas eurytopic and stenotopic species characterised the inner and outer shelves.

A new species of the genus Petalophthalmus (Crustacea: Mysida: Petalophthalmidae) is described, based on specimens collected from the Galicia Bank (northeastern Atlantic Ocean). This species can be distinguished from the other species of the genus Petalophthalmus by the presence of an ocular papilla on its eyes. P. papilloculatus sp. nov. is morphologically close to the cosmopolitan species P. armiger Willemoes-Suhm, 1875, but can be easily distinguished by the presence of an ocular papilla, the longer antennal scales bearing an apical lobe, the unique chitinous ridge on the molar process, the outwards lengthening of the three cuspidate setae on the outer margin of the uropodal exopod and the armature of the telson. This new species lives on fine and very fine sandy bottoms at the bank flanks, between 1536 and 1809 m depths. Probably related to the special biogeographic characteristics of seamounts, the morphological affinity between the new species and P. armiger supports the hypothesis on a common ancestry and recent divergence between both deep sea mysids. An identification key to world species of Petalophthalmus is provided.

A new species of the genus Liropus (Crustacea, Amphipoda, Caprellidae) is described based on specimens collected from Le Danois bank (‘El Cachucho’ fishing grounds), Bay of Biscay. Liropus cachuchoensis n. sp. can be distinguished from all its congeners mainly by the absence of eyes and by the presence of a dorsal projection proximally on pereonites 3, 4 and 5 in males, on 3 and 5 in females. The new species has been found living on muddy bottoms on the southern flank of the bank and adjacent continental slope, between 619 and 1062 m depth, with a maximum abundance (56.1 ind./100 m 2 ) recorded at 1044–1062 m. Morphological comparisons among the world's members of Liropus , a key to species, and data on their distribution are presented.

A new paranthurid isopod, Paranthura santiparrai sp. nov. is described from specimens collected in the 'El Cachucho' Marine Protected Area, southern Bay of Biscay. The new species can be distinguished from all the known species of the genus Paranthura by the absence of eyes, from the native NE Atlantic species Paranthura nigropunctata and Paranthura costana by the lack of body pigmentation, antenna 1 and pereopod morphology and from the non-indigenous species Paranthura japonica (recently discovered in the Arcachon Bay) by the pleonites not fused mediodorsally. The genus Paranthura is rediagnosed to accommodate the new taxon and an identification key is provided for European species. Ecological data on the new species are presented.