Hábitos alimentarios del tiburón martillo Sphyrna lewini (Griffith & Smith, 1834) (Chondrichthyes) en el Pacífico ecuatoriano

This study analyzed the diet of 116 specimens of scalloped hammerhead, Sphyrna lewini caught by the shark fleet in the Ecuadorian Pacific. The sampling was between January and December 2004. The index of relative importance (%) showed the highest values for the cephalopods Histioteuthis spp. (22.7%) and Dosidicus gigas (21.9%). In relation to feeding by maturity stage and sex, the juvenile females predated mainly on D. gigas (58.5%); whereas the adult females feed mainly on Octopus spp. (47.6%), Histioteuthis spp. (18.7%) and Sthenoteuthis oualaniensis (16.3%). The juvenile males fed on cephalopods Mastigoteuthis spp. (12.1), Histioteuthis spp. (10.2) and Ancistrocheirus lesueuri (7.9), while the adult males predated on D. gigas (53.7%) and Histioteuthis spp. (14.9%). Considering the prey habitat, S. lewini is an oceanic predator which consumed oceanic prey, mainly cephalopods; whereas the juvenile sharks can predate on oceanic cephalopods and also on coastal prey from benthic habitat such as fish and crustaceans.