Published online by Cambridge University Press: 11 May 2009
On the 16 June 1982 a thresher shark, Alopias vulpinus (Bonnaterre, 1788), became entangled in a gill net at Bigbury Bay, S. Devon. The stomach contents were found to consist solely of teleost otoliths. The soft tissues of prey taken by large marine predators are often macerated and digested very rapidly or, as in this case, regurgitated during capture or stranding. Identification of the prey is therefore only possible from the hard parts which often remain, e.g. teleost otoliths, bones and scales, and cephalopod beaks, statoliths and gladiuses. The regular seasonal occurrences in the waters off south-west England and south-west Ireland make the thresher the most common of the large sharks in this area. Their accidental capture or collisions with nets are not rare and they have been taken by rod and line on several occasions.