Is the lesser spotted dogfish (Scyliorhinus canicula) population from the Cantabrian Sea a unique stock?

Abstract

Abstract A summary of the information recorded from tagging surveys since 1993 for Scyliorhinus canicula in the southern part of the Bay of Biscay (ICES Division VIIIc) is presented. In total 6619 specimens were tagged, with the recapture rate being around 2.3%. The maximum distance recorded was 158.9 miles, while 70% of the specimens recaptured were within less than 15 miles and 56% less than 10 miles. From these data, a priori, we can affirm that this species remains in certain areas, making short movements. No differences were found between males and females and no seasonal pattern was detected. Apparently, there was no relation between time at liberty and distance covered. Spatial and bathymetric distribution of both juveniles and adults are presented and combined with previous data to describe the habitat of this species. The distribution of S. canicula is continuous along the continental shelf although they may aggregate by sex and/or size. Juveniles are mostly found in the southern corner of the Bay of Biscay at depths around 200 m, while adults have a wider depth distribution (50–450 m). The temperature distribution in the study area ranged from 11 to 18 °C in the autumn surveys. Juveniles were usually found in waters around 12 °C, while adults were more abundant in waters around 14–15 °C.