Feeding strategy of yellowfin tuna (Thunnus albacares), and wahoo (Acanthocybium solandri) in the Saint Peter and Saint Paul Archipelago, Brazil

Abstract

Food composition, predator-prey relationships and feeding strategy of yellowfin tuna, Thunnus albacares, and wahoo, Acanthocybium solandri, in the Saint Peter and Saint Paul Archipelago were studied. A total of 806 stomachs were collected during trolling and hand line commercial fishing from 1994 to 2002. Twenty-five food items were identified for the two predators together, including fifteen fishes, six cephalopods, three crustaceans and one tunicate. A remarkable predation of T. albacares and A. solandri upon the flying fish Cypselurus cyanopterus was observed around Saint Peter and Saint Paul Archipelago, mainly between November and April. This was directly related to the main reproduction period of C. cyanopterus. There was no relationship between size and number of food items, and body size of the predators. Food overlapping between predators was 4.8% similar in the number of preys, and 89.9% similar in weight of preys. The archipelago is a feeding ground for T. albacares between November and April, and throughout the year for A. solandri.