Assessing trophic interactions between pelagic predatory fish by gut content and stable isotopes analysis around Fernando de Noronha Archipelago (Brazil), Equatorial West Atlantic

The objective of this study was to analyse the feeding habits and trophic interactions between four oceanic predatory fish around Fernando de Noronha Archipelago (FNA), Brazil, in western equatorial Atlantic (3.86°S/32.42°W), internationally recognized as an environment high economic ecological value. For purpose, biological samples yellowfin tuna (Thunnus albacares), wahoo (Acanthocybium solandri), barracuda (Sphyraena barracuda) dolphinfish (Coryphaena hippurus) were collected for stomach content stable isotope analysis. Values index relative importance revealed varied diets, with a strong presence teleost fishes (Diodontidae Exocoetidae) all species, having greater diversity food items. Despite being generalists/opportunists, strategy these predators showed tendency towards specialized diet use available resources FNA. They presented narrow niche width (Levin's index, Bi < 0.6) low overlap except (MacArthur Levin's, R0 = 0.72). Isotopic compositions had broad values ?13C ?15N, significantly different species. Our results provide information about species' organization suggest that avoid competition by preying on prey, thus allowing their coexistence.