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

Abstract

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.