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
