2016 by Taylor & Francis Group, LLC. Bluefin tunas are large pelagic fishes that primarily prey on fishes and squids (Collette and Nauen 1983). The feeding ecology of bluefin tunas has been studied in depth primarily due to their high value in commercial and recreational fisheries (Collette and Nauen 1983). Because stock biomass and growth rates of bluefin tunas are potentially influenced by prey abundance, having a good understanding of species interactions in oceanic ecosystems is important. Furthermore, fishing grounds of bluefin tuna may be formed in prey abundant areas, thus fishermen have a vested interest in preference of bluefin tuna prey. In contrast, abundance of commercially important fishes and squids could also be influenced by abundance of predatory tunas. In the aquaculture field, information of prey species in their natural condition is useful to develop equivalent food for captive individuals. Consequently, the feeding ecology of bluefin tunas is important throughout all ocean basins.
