Ophiuroidea of the Avilés Canyons System (INDEMARES + LIFE Project).

The Avilés Canyons System (ACS) is located in the Cantabrian Sea (Bay of Biscay) and is composed of three canyons. It was declared Site of Community Importance (SCI: C ESZZ12003) within the Natura 2000 Network (Ministry of Agriculture, Food and Environment, 2014) due to their diversity of species and vulnerable habitats (Sánchez et.al., 2014). During the years 2010 - 2012 several campaigns of the INDEMARES LIFE - ACS project were carried out. This study includes the zone that goes from the beginning of the continental slope to the maximum depth sampled in the bathyal zone (depth range between 266 and 2291 m). A total of 7413 specimens which correspond to 48 species, were collected from 50 stations. The most abundant species were Ophiocten affinis (Lütken, 1858) with 4092 specimens and Ophiothamnus affinis Ljungman, 1872 with 1842. The most frequent ones were Ophiactis abyssicola (M. Sars, 1861) and Ophiacantha bidentata (Bruzelius, 1805) present in 48% and 26% of stations respectively. Comparing our species with public databases (OBIS, GBIF) and the bibliography, five potential new records have been found for the Cantabrian Sea, part of the North-Atlantic Marine Subdivision (Lavín et. al., 2012).Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Estructura y crecimiento absoluto de una población de Hippolyte inermes Leach 1815 (Decapoda: Caridea) de las praderas de Zostera marina (L.) (Málaga, Sur de España).

The Hippolyte inermis Leach 1815 population from Zostera marina beds in southern Spain showed two recruitment periods that occurred simultaneously for both sexes (from September to December and from April to June), in a size range between 1.67 and 1.90 mm carapace length, due to gonadal activity and eggs hatching in summer and winter. The estimated Von Bertalanffy parameters were used to determine absolute growth and showed that males live for around 8 months and females for around 12 months; consequently, four cohorts for males and 7 to 8 for females can coexist throughout the cycle. The sex ratio favours females throughout the entire life cycle. Data published on the reproductive biology of H. inermis support the idea that this is a protandric hermaphrodite species, though recent studies have revealed that there is no histological proof of hermaphroditic sexuality in adult specimens of this species. The results obtained here indicate that the Cañuelo Beach Hippolyte inermis population has a gonochoric structure. If H. inermis were to have hermaphroditic sexuality, the sex reversal of adult males would occur in a single moult in the size range between 2.42 and 3.22 mm. These new, secondary females would be incorporated into the primary female cohort at practically the same size, although they would be 0.12 to 5.20 months younger. Our results, compared with those from other population studies, suggest that this species has a highly plastic population structure, which seems to be determined by external factors and which varies between the protandric and gonochoric condition, depending on the conditions of the habitat.El estudio de una población de Hippolyte inermis Leach 1815 de fondos de Zostera marina del Sur de España muestra dos periodos de reclutamiento simultáneo para ambos sexos, de septiembre a diciembre y de abril a junio, en un rango de talla de 1.67-1.90 mm como consecuencia de la maduración gonadal y la eclosión de la puesta en verano e invierno. El estudio de los parámetros de Von Bertalanffy muestra que el modelo de crecimiento absoluto es de tipo indeterminado y que los machos viven alrededor de 8 meses, mientras que las hembras son más longevas (12 meses); consecuentemente durante el período de estudiado coexisten 4 cohortes para los machos y 7-8 para las hembras. El estudio de crecimiento poblacional revela que éste viene determinado por el de las hembras, ya que el sex-ratio siempre es a favor de estas últimas. Datos publicados sobre Hippolyte inermis apoyan que se trata de una especie hermafrodita proterándrica, aunque estudios histológicos en adultos no apoyan esta hipótesis. En el caso de la población estudiada, el conjunto de resultados obtenidos justifican sobradamente que se trata de una población gonocórica. Si existiera cambio de sexo en los machos adultos este se produciría en una sola muda, en el rango de talla de 2.42-3.22 mm y estas nuevas hembras se incorporarían a las cohortes de hembras primarias de la talla más o menos similar pero entre 0.12-5.20 meses más jóvenes. Los resultados obtenidos, en comparación con otras poblaciones de otras áreas geográficas, muestran que posiblemente esta especie tenga una estructura y dinámica poblacional muy versátil, pudiéndose manifestar como una especie proterándrica o gonocórica dependiendo de factores externos propios de cada hábitat

Preliminary characterization of echinoderm assemblages in circalittoral and bathyal soft bottoms of the northern Alboran Sea

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 weighed to the nearest 0.5 g. Abundance and biomass data were standardized to 1000 m2 according to the sampling area of each haul. Echinoderm assemblages were characterized according to the dominance and frequency of occurrence of species in the samples and considering different ecological indexes. Multivariate methods (CLUSTER, nMDS, SIMPER, ANOSIM) were applied, based on the Bray & Curtis similarity index, for detecting and contrastingassemblages in relation to depth and 4 geographic areas of the Alboran Sea with different influence of Atlantic waters (Occidental-Esteponato Málaga, Central-Málaga to Motril, Oriental-Motril to Almería and Alboran Island). Fig. 1. Location of beam-trawl samples (dots) collected during 2014 and 2015 MEDITS expeditions in the northern Alboran Sea. At present 39 taxa have been detected, mostly belonging to Ophiuroidea and Asteroidea (28.2 and 25.6% of all species, respectively), followed by Holothuroidea (23.1%), Echinoidea (17.9%) and Crinoidea (5.1%). Regarding abundance, a total of 54689 individuals have been collected, being Ophiuroidea (98.6% of all individuals), Holothuroidea (0.6%) and Crinoidea (0.4%) the top-dominant classes. Regarding biomass, ophiuroids also dominated (52.8%), followed by asteroids (16.1%) and holothuroids (15.0%). Considering other faunistic groups, echinoderms were the most abundant phyllum in the samples (60.7%) and the fifth one in biomass (7.6%). The dominant (for both abundance and biomass) and frequent genera included Ophiocten (displaying dominances >90%) Hymenodiscus, Luidia and Astropecten for asteroids, Antedon and Leptometra for crinoids, Dendrochirotida and Molpadidae for holothuroids, and Brissopsis and Echinocyamus for echinoids (Fig. 2). Fig. 2. Some echinodermscollected in circalittoral and bathyal soft bottoms of the Alboran Sea using beam-trawl during the MEDITS expeditions. A: Ophiocten; B: Dendrochirotida sp.; C: Brissopsis; D: Anseropoda; E: Luidia. Multivariate analyses indicated groupings of samples and significantly different echinoderm assemblages in relation to depth (RANOSIM=0.22, p0.05). Shelf assemblages displayed lower intra-group similarities (<20% similarity in SIMPER) than the slope ones (ca. 40%). Species characterizing the shelf assemblages belonged to the genera Astropecten, Antedon, Ophiothrix among others, whereas those of the slope belonged to the genera Luidia (L. sarsi), Hymenodiscus, Ophiocten, Leptometra and Amphiura

Caracterización ecológica del área marina del banco de Galicia

Se integra información hidrográfica, geomorfológica, sedimentológica, biológica, sobre hábitats marinos y pesquera, para establecer las bases ecológicas necesarias para la protección y conservación del banco de GaliciaEl 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 100 especies como son moluscos, peces (con especial énfasis en los elasmobranquios), crustáceos y cnidarios. Este inventario incluye especies nuevas para la ciencia, primeras citas para aguas españolas y europeas y especies de gran interés científico y biogeográfico. Este último punto se explica por la situación del Banco entre regiones biogeográficas conectadas por corrientes y masas de agua. El estudio de las conexiones tróficas entre este elevado número de especies ha mostrado el reforzamiento de las rutas bentopelágicas (gambas y macrozooplancton) frente a las dietas epi- y endobentónicas más habituales en otros fondos equivalentes. Mediante técnicas de muestreo extractivas (arrastres, dragas) y de vídeo, y su proyección sobre la interpretación geomorfológica realizada a partir de la sonda multihaz, se ha obtenido una estimación de la distribución de los hábitats bentónicos del banco. Los hábitats identificados en fondos sedimentarios son 1) arenas medias con ofiuras Ophiacantidae y Flabellum chunii, 2) arenas medias con arrecife de corales profundos de Lophelia pertusa y/o Madrepora oculata, y 3) arenas finas con holoturias elasipódidas (Benthogone rosea). En fondos rocosos se han caracterizado los hábitats de 4) roca batial sin pendiente con gorgonias y corales negros, 5) roca batial de talud con comunidades de corales y esponjas, 6) roca batial de talud con corales blancos, bambú y negros, gorgonias y esponjas, 7) arrecife de corales profundos de Lophelia pertusa y/o Madrepora oculata y 8) roca con nódulos manganésicos. El único tipo de hábitat de la DH descrito en la zona es el 1.170 (arrecifes). Sólo se han incluido en la Directiva Hábitats como 1.170 aquellos que presentaban una densidad y diversidad suficientes para cumplir la definición de “arrecifes”. De los hábitats descritos en el banco (ver características ecológicas y biológicas más arriba) solo se han incluido en el 1.170 los arrecifes de corales blancos situados en las arenas medias de la cima del banco, los arrecifes de corales blancos de aguas frías de las especies Lophelia pertusa y Madrepora oculata sobre la roca de la cima del monte Rucabado, las comunidades de roca batial de talud de la ladera sur del banco constituidas por colonias de corales blancos de aguas frías de las especies Lophelia pertusa y Madrepora oculata, y una fauna acompañante muy diversa de escleractinias solitarias, corales bambú, corales negros, gorgonias y esponjas de gran porte, y el resto de zonas de roca batial de talud con comunidades de corales y esponjas. Muchos de los hábitats pueden ser incluidos en los listados de hábitat vulnerables de OSPAR, en los tipos jardines de coral, agregaciones de esponjas de profundidad, arrecifes de Lophelia y montículos carbonatados. En cuanto a las especies de interés para la protección, de las citadas en el banco, el delfín mular (Tursiops truncatus) y la tortuga boba (Caretta caretta) son las únicas especies que figuran en el Anexo II de la Directiva de Hábitats. Sin embargo, muchas epecies de elasmobranquis y algunos peces óseos son consideradas vulnerables, amenazadas o en declive según los criterios definidos por OSPAR y la lista roja de especies amenazadas de IUCN. Algunas de están protegidas por el reglamento europeo 1262/2012 que regula la pesca de especies profundas. La lejanía del banco respecto a los principales focos de presión y la ausencia casi total de presión pesquera hace que el grado de conservación sea muy alto, pudiéndose hablar de un ecosistema prácticamente prístino. Las recomendaciones para la gestión de esta zona van encaminadas a garantizar esta calidad ambiental actual.Instituto Español de Oceanografía, Comisión Europea Programa LIFE+, Fundación Biodiversida

Deep-sea echinoids from the Avilés Canyons System (Cantabrian Sea: North Atlantic Ocean).

12 pagesInternational audienceThe Avilés Canyons System (ACS) is located in the South of the Bay of Biscay (Northern Spain, Cantabrian Sea) and covers a total of 3,390 km2. It is composed of three canyons, reaching the abyssal plain at 4700 m depth. The mixing of diverse water masses generates gyres and upwellings that contribute to the enrichment in nutrient concentration at different depth and favour the settlement of benthic communities. The ACS has been declared Site of Community Importance (SCI: C ESZZ12003) within the Natura 2000 Network and recognized as a Vulnerable Marine Ecosystem where echinoderms play an important ecological role in benthic communities and habitats.The aim of the present study is to inventory and review the echinoid fauna collected during the INDEMARES project in the ACS, compare the new findings with previous studies Official Spanish Checklist (IEEM: “Inventario Español de Especies Marinas”, 2017, 2020) and update our knowledge of the diversity and distribution of echinoid species.During the surveys carried out within the project LIFE + INDEMARES-Avilés Canyons System (2010–2012), a total of 287 specimens of echinoids were sampled at 35 stations and depth ranging between 510 and 1476 m. Twelve species of echinoids were identified, the most frequent being Araeosoma fenestratum (Thomson, 1872) (48.57%), Cidaris cidaris (Linnaeus, 1758) (42.85%) and Phormosoma placenta Thomson, 1872 (28.57%). One species should be considered as a new record in Spanish waters, Gracilechinus affinis (Mortensen, 1903) and the species Echinocardium flavescens expands its known bathymetric range (from 325 to 552 m)

Deep sea starfishes (Echinodermata: Asteroidea) from the Avilés Canyon System (Bay of Biscay), including two new records

The Avilés Canyon System (ACS) is located at the Southern Bay of Biscay (Northern Spain, Cantabrian Sea). The ACS occupies a total of 339.026 ha and is composed of three canyons, reaching the abyssal plain at 4700 m depth. Water masses that mix in the area form gyres and upwelling that contribute to increasing the nutrients at different depths, which makes it an important place for the settlement of benthic communities. They have been declared Site of Community Importance (SCI: C ESZZ12003) within the Natura 2000 Network and recognized as a Vulnerable Marine Ecosystem where Echinoderms play an important role in these communities and habitats. The present study tries to inventory and review asteroid fauna collected during the INDEMARES project in the ACS and compare the new findings with previous studies Official Spanish Checklist (IEEM: “Inventario Español de Especies Marinas”, 2017, 2020) to update our knowledge on the diversity and distribution of the asteroid's species. During the surveys carried out within the project LIFE + INDEMARES-Avilés Canyon System (2010–2012) a total of 445 specimens, belonging to 25 Asteroids species, were collected from 36 stations in a depth range between 266 and 1476 m. The most frequent species were Nymphaster arenatus (Perrier, 1881) (30.55%) and Henricia caudani (Koehler, 1895) (25%). After public datasets, two species should be considered as new records for Spanish waters: Radiaster tizardi (Sladen, 1882) and Henricia sexradiata (Perrier, 1881), and 4 species expand their bathymetric range: Novodinia pandina (Sladen, 1889), H. caudani, H. sexradiata (Perrier, 1881) and Myxaster perrieri Koehler, 1895

Deep-Sea asteroids (Echinodermata; Asteroidea) from the Galician Bank (North Atlantic Ocean)

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.Peer reviewe

Looking for morphological evidence of cryptic species in Asterina Nardo, 1834 (Echinodermata: Asteroidea). The redescription of Asterina pancerii (Gasco, 1870) and the description of two new species

Three species of the genus Asterina are known to inhabit the Mediterranean Sea and the north-eastern Atlantic Ocean: Asterina gibbosa (Pennant, 1777), A. pancerii (Gasco, 1870) and A. phylactica Emson & Crump, 1979. Differentiation of these species has primarily been based only on subtle characters (some highly debatable), such as colour or size. Therefore, this study aimed to review the morphological data characterising members of the genus, to incorporate new characters that may clarify morphological analyses and to couple morphological data with molecular evidence of differentiation based on the analysis of partial sequences of the cytochrome c oxidase subunit I (COI) and 18S rDNA (18S) genes and two anonymous nuclear loci (AgX2 and AgX5). The different lineages and cryptic species identified from the molecular analysis were then morphologically characterised, which was challenging given the limited number of diagnostic characters. Two of the five monophyletic lineages obtained molecularly (COI divergence >4%), further supported by differences in morphological characters and reproductive behaviour, are proposed as new species: Asterina martinbarriosi, sp. nov. from the Canary Islands, Spain (eastern central Atlantic Ocean) and Asterina vicentae, sp. nov. from Tarragona, north-eastern Spain (western Mediterranean Sea).This study was supported by Spanish Research State projects (Ref. CGL2011-23306 and CTM2014-57949-R)