Stomach contents of yellowfin tuna caught by commercial tuna longliners in Southern Brazil, were studied from 178 specimens collected during Winter and Spring between August 1988 and October 1990. IRI (Index of Relative Importance) diagrams and a prey list showed variations in the diet composition for both seasons. Teleosteans and the squid Ornithoteuthis antillarum were the most important items during Winter, whilst the amphipods hyperiids Brachyscelus crusculum and Phrosina semilunata were the main items during Spring. Yellowfin tuna is an euriphagic predator, that practice no discrimination on prey type nor prey size.
Yellowfin tuna; stomach contents
