Animal’s trophic ecology is an important subject, as it helps establishing connections between various aspects of species’ biology and it’s relation to the environment. Feeding behavior and diet are crucial features, involved in species distribution and occurrence pattern in the environment, their functional role in the ecosystem and also in communities’ structure. Moreover, these studies provide necessary knowledge to the conservation of natural environments, such as reef ecosystems. The feeding behavior of butterflyfishes (Chaetodontidae family) is well documented in the Indo-Pacific, Red Sea and Caribbean regions, meanwhile there are currently unknown aspects when it comes to some chaetodontids of the Atlantic Ocean. Chaetodon ocellatus’ distribution is restricted to the Atlantic, where it occurs from the coast of the United States till the state of Espirito Santo, Brazil. In this study the three levels of the species’ trophic ecology were assessed, that being it’s foraging behavior, diet and nutrient assimilation. This integrative approach bared great importance, due to the differences found between the selectivity of foraging micro-habitats and the species’ diet. The isotopic analysis of atoms of carbon-13 and nitrogen-15 demonstrated that C. ocellatus belongs to a low trophic level, what corroborates with the results found for the diet (>80% of the volume was composed by the zoanthid Zoanthus sociatus). C. ocellatus is a specialist, differently from the other butterflyfishes of the genus Chaetodon of the Atlantic, which are generalists.