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The Galician Bank (GB) is a seamount located 180 km away from the Galician coast (Northwest Spain), in the Northeast Atlantic Ocean. The summit occurs at a depth between 650 and 1500 m with the maximum depth reaching 4000 m (the abyssal bottom). The water masses, twists, eddies, and geomorphology favour the retention of nutrients and larvae, thus, being an area rich in nutrients. It is a hotspot of biodiversity and an important place for benthic communities. This study aims to inventory and review the asteroid fauna collected during the LIFE+INDEMARES project in GB, compare the new findings with previous studies Official Spanish Checklist (IEEM: "Inventario Español de Especies Marinas", Manjón-Cabeza et al. 2017, 2020) and update our knowledge of the diversity and distribution of known species. In this study a total of 272 asteroid specimens belonging to 19 species were found at 45 stations in depths between 765-1764 m, as part of the LIFE+INDEMARES-Galician Bank (2010-2011) surveys. The most frequently encountered species were Plinthaster dentatus (Perrier, 1884), Peltaster placenta (Müller & Troschel, 1842) and Henricia caudani (Koehler, 1895). Circeaster americanus (A.H. Clark, 1916) and Hymenaster giboryi (Perrier, 1894) are new observations from this area. For several species, including Henricia caudani, Pedicellaster typicus M. Sars, 1861, Podosphaeraster thalassae Cherbonnier, 1970 and Hymenaster giboryi known bathymetric range has been extended.

This study analyzes the fauna composition of the community of brittle and sea stars associated with sponge aggregations located in Avilés Canyons System and El Cachucho, Marine Protected Area (MPA). Diverse sampling methods were used depending on bottom morphology, such as rock dredges and specific samplers for sedimentary bottoms, mainly beam trawl models. These banks are made up of sponge and coral species that build a very appropriate substrate for the proliferation of benthic species, which together create Vulnerable Marine Ecosystems that are highly relevant for management and conservation. Among these benthic species, echinoderms are of great interest due to their value as indicators of good habitat. In total, 1261 specimens were collected (934 brittle stars and 327 starfishes), belonging to 42 species (28 ophiuroids and 14 asteroids) from INDEMARES AVILÉS, ECOMARG, and SponGES project surveys. Specimens were distributed among four sponge aggregations (F: fields) that were considered according to the sponge records obtained in the same stations (36). These fields were defined and named based on the five most common sponge species: Aphrocallistes beatrix and Regadrella phoenix (F1: Avilés Canyon); Pheronema carpenteri (F2: Intraslope basin of Le Danois Bank); Asconema setubalense (F3: Le Danois Bank); and Neoschrammeniella aff. bowerbankii (F4: Corbiro Canyon). Faunistic results show that Ophiactis abyssicola (55.55% occurrence), Brisinga endecacnemos, Ophiolycus purpureus, and Peltaster placenta (33.33%) were the most frequently found species in F1; Psilaster andromeda (80%), Pseudarchaster parelii (60%), and Nymphaster arenatus (46.67%) in F2; Ophiura carnea (71.43%) and Ophiacantha smitti (42.86%) in F3; and Ophiacantha densa, and Henricia caudani (100%) in F4. The asteroid and ophiuroid species collected seem to be composed of four different communities that fit to areas with particular morphological and biological features, related to the presence of speci

Echinoderms, with 7.272 species described so far (based on WORMS), provide an ecosystemic role which can be important depending on their habitat, and including tag species (Manjón-Cabeza et al., 2014; Palma-Sevilla 2015) or even dominant ones (Iken et al., 2010; Hughes et al., 2012). Despite the increasing knowledge on their taxonomy, studies on ecological and assemblage composition and structure of echinoderms are very scarce compared to those for other invertebrate groups, being this information essential for improving the knowledge on Mediterranean ecosystems (Coll et al., 2010). The Alboran Sea, in the junction of the Atlantic Ocean and the Mediterranean Sea and the European and African continental margins, represents a biodiversity hotspot due to the overlapping of species from those basins and continents, including some endemic components (Coll et al., 2010). Regarding echinoderms of the Alboran Sea, most previous studies focussed on infralittoral bottoms, with very few for circalittoral and bathyal ones (Manjón-Cabeza et al, 2014; Sibuet, 1974). Nevertheless, these studies generally included faunistic lists (Ocaña & Pérez-Ruzafa, 2004; Manjón-Cabeza et al., 2014), sometimes with identification keys, ecological and distributional data of some species and rarely on the assemblage composition and structure (Palma-Sevilla, 2015), which represent the main aim of this study on echinoderm assemblages of circalittoral and bathyal soft bottoms of the Alboran Sea. During the MEDITS survey expeditions (April-May 2014-2015) on board the R/V Miguel Oliver (Fig. 1), 35 samples were collected using a beam trawl (horizontal and vertical openings of 1.3 and 1.2 m, respectively, and a mesh size of 10 mm in the codend) at depths from 40 to 774 m in the Alboran Sea (Fig. 1). Hauls were done at a speed of ca. 2 knots during 5-10 (shelf stations) and 15 minutes (slope stations). Echinoderms were separated, identified to the lowest possible taxonomic leveland specimens counted and

El banco de Galicia es un monte submarino profundo situado a 180 km de la costa gallega, con una cima situada entre los 650 y los 1.500 m de profundidad y rodeado de zonas abisales de más de 4.000 m de profundidad. El relieve de las montañas submarinas interactúa con la circulación oceánica modificando las condiciones de oligotrofismo imperantes en el mar profundo. El cambio de dirección de las corrientes marinas, al chocar con el banco, produce las llamadas columnas de Taylor que tienen como consecuencia giros sobre la cima y finalmente un enriquecimiento de las aguas que bañan el banco, lo que influye, a través de la cadena trófica, en las especies de cetáceos, aves y tortugas. Estas condiciones, junto al aislamiento de estos bancos, convierten a estos bancos en puntos calientes de biodiversidad. Esta teoría se ha visto corroborada por los estudios realizados en el proyecto INDEMARES, basados en dos campañas de investigación, dónde se ha encontrado una elevada biodiversidad y la presencia de hábitats vulnerables. El banco de Galicia está bañado por tres capas diferentes: la masa de agua central del Atlántico nordeste europeo (East North Atlantic Central Water: ENACW), por debajo de las aguas superficiales y hasta los 500-600 m; la masa de agua mediterránea (Mediterranean Outflow Water: MOW) y la masa de agua del Labrador (Labrador Sea Water: LSW), que es la capa más profunda. En cuanto al tipo de fondo, se encuentra roca en el área del flanco oriental y hacia el sureste y en los montes adyacentes como el Rucabado, distinguiendo claramente dos tipos en cuanto a la pendiente, correspondiendo con la roca plana de la cima y la roca en pendiente del borde del banco y paredes. En la cima se encuentran fondos de arenas medias, de reflectividad media y baja según el espesor de sedimento, y arenas finas en los fondos sedimentaruios de los flancos, a profundidades mayores de 1.500. En el banco se han identificado hasta el momento 793 especies, con taxones que superan las 10

En esta comunicación se vierten los resultados preliminares obtenidos durante una serie de 13 campañas, enmarcadas dentro del proyecto ATLANTIS, en el periodo comprendido entre Octubre de 2007 y Abril de 2010 a bordo del buque oceanográfico Miguel Oliver, utilizando diversos equipos: draga megabox corer, draga de roca, arte de arrastre LOFOTEN,CTD y colector de sedimentos. Este proyecto trata del estudio de los ecosistemas marinos vulnerables en aguas del Atlántico sudoccidental desde la perspectiva de la gestión pesquera de aguas profundas de alta mar realizadas por el Instituto Español de Oceanografía. La zona de estudio comprende estaciones de muestreos desde la amplia plataforma de las zonas costeras de la Patagonia, las zonas más profundas de los cañones submarinos más allá del talud (107m – 1393m). Esta zona es rica en esponjas y grandes jardines de coral y gorgonias que favorecen el asentamiento y la asociación de muchas especies, entre ellas las de equinodermos. En este sentido, el estudio de los equinodermos patagónicos y por lo tanto argentinos, tuvo una especial atención durante más de 40 años gracias a los trabajos de Bernasconi desde los años 40 hasta los 80, centrándose principalmente en Asteroideos y Ofiuroideos, aunque también abordó muchos trabajos de ámbito general de los equinodermos presentes en distintas zonas costeras argentinas. Aunque en ellos se incluían listados de Holoturoideos, no se profundizó en este grupo, a pesar de escasos trabajos como los realizados por Hernandez en Puerto Deseado en 1981. Recientemente se han retomado estos estudios, y en el caso de las holoturias, los principales trabajos están realizados por distintos investigadores del Museo Nacional de Ciencias Naturales (Martínez et al., 2009; Martinez & Penchaszadeh, 2011), que abarcan estudios generales o revisiones taxonómicas, principalmente de dos familias Sclerodactylidae y Psolidae. En el área de estudio han sido registrados 556 ejemplares, pertenecientes a 14 especies

The Bellingshausen Sea is one of the most remote and least surveyed seas of the Southern Ocean, so that little was known about benthic communities and those factors that determine community structuring until recently. The present work aims at characterizing the structure and spatial distribution of echinoid assemblages in the Bellingshausen Sea, as well as identifying the environmental factors that determine assemblage structuring. Echinoids were collected at 32 stations using an Agassiz trawl, at depths of 86–3,304 m, during BENTART oceanographic expeditions led in 2003 and 2006. Sediment and bottom water properties were analysed using an USNEL-type box corer and a Neil Brown Instrument System Mark III CTD, respectively. Echinoids were found at all stations, except Peter I Island. Seventeen species were identified, representing 22 % of the echinoid species present in the Southern Ocean and increasing twofold the number of species recorded in the Bellingshausen Sea so far. The echinoid fauna is dominated by the very abundant species Sterechinus antarcticus. Depth is the key factor that determines the nature of echinoid assemblages, which are mainly divided into the continental shelf, the slope and the deep-sea basin. In addition, sediment properties, namely redox values, organic matter and mud content, best match species dispersion on the shelf. Sediment properties affect echinoid distribution depending on species food range and feeding strategy. As it might be expected, sediment properties more strongly influence specialist feeders (Schizasteridae and Cidaridae) than generalists (Echinidae).

The structure and spatial distribution of the macrofauna community of the Bellingshausen Sea in the western sector of Antarctica was studied during the ‘BENTART–06’ oceanographic expedition. This is one of the least explored Antarctic seas. A total of 20 box cores were sampled at 11 stations ranging from 157 to 3,304 m depth, using an USNEL-type box corer (BC) dredge. Representatives of 25 higher taxa of invertebrates were collected. Deeper sampling sites were less rich in taxa (4–7 taxa), whereas the figures were higher at shallower sites (up to 17 taxa). Faunal density on the sea bottom revealed a horizontal spatial gradient from the western sites with extremely low figures (90 indiv./m2) towards the eastern ones with the highest figures (1,360 indiv./m2) close to the Antarctic Peninsula. Several abiotic factors (depth, redox, organic matter, carbonates and particle size of surficial sediments) were measured simultaneously on the sea floor to characterise the substrate preferences of the fauna. Positive correlations were found between the faunal distribution and a combination of depth, redox values, and organic matter content of sediments. This indicates decreasing availability of food in the deeper bottoms of the Bellingshausen Sea with a prevalence of depauperated bottoms dominated almost exclusively by a foraminiferans community.

During the Bentart-2003 Cruise, carried out during austral summer 2003 in the Bellingshausen Sea, three species of Lithodidae, Paralomis birsteini, Lithodes murrayi and Neolithodes capensis, were caught from 218 m to 1947 m. With these captures the presence of L. murrayi in Peter I Island is confirmed, the distribution area of N. capensis is greatly increased and the captures of N. capensis and P. birsteini represent the first lithodid record known from the Antarctic continental slope. Also, these records show large and discontinuous distributions, which illustrate that many distribution patterns of Antarctic species are more an artefact of limited studies than representing actual distribution

During the BENTART 95 survey, epifauna was sampled with an Agassiz trawl at 24 stations ranging from north of Livingston Island (South Shetland Islands) to the Antarctic Peninsula at depths from 40 to 850 m. Four assemblages of ophiuroids were identified and correspond to Deception Island, Trinity Island, and the southern and northern zones of Livingston Island. In addition to these regions, gradients related to depth and filter-feeder biomass were found. The brittle-star assemblages were dominated by Ophionotus victoriae Bell, 1902, which to a large extent determine the biogeographic structure in the South Shetland Islands.