Results on main elasmobranch species captured in the bottom trawl surveys on the Northern Spanish Shelf

Abstract

This working document presents the results on the most abundant elasmobranch species captured in the 2020 Spanish Groundfish Survey on Northern Spanish shelf. Biomass, spatial distribution and length ranges were analysed for Scyliorhinus canicula (lesser spotted dogfish), Galeus melastomus (blackmouth catshark), Etmopterus spinax (velvet belly), Raja clavata (thornback ray), Raja montagui (spotted ray), Leucoraja naevus (cuckoo ray) and other scarce elasmobranches. In general the biomass of these species remained high this last survey, despite the slight decline observed on S. canicula (lesser spotted dogfish), R. clavata (thornback ray) and R. montagui (spotted ray). A few specimens of the scarce elasmobranches Scymnodon ringens (knifetooth dogfish), Dalatias licha (kitefin shark), E. pusillus (smooth lanternshark), R. undulata (undulate ray) and L. circularis (sandy ray) were found as usual in this last survey whereas the occasional species Mustelus mustelus (smooth-hound), Neoraja iberica (iberian pygmy skate), Dipturus nidarosiensis (norwegian skate) and R. microocellata (small-eyed ray) were not. Gaelorhinus galeus (tope shark), Tetronarce nobiliana (electric ray), Dipturus oxyrinchus (longnosed skate), Torpedo marmorata (marbled electric ray) and Raja brachyura (blonde ray) were captured again since time ago in the time series and Centroscymnus crepidater (longnose velvet dogfish) was found for the first time in the historical series. Signs of recruitment were found for G. melastomus, G. atlanticus, R. clavata and L. naevus.