Dieta e sobreposição de nichos de duas espécies de gerreídeos, Eugerres brasilianus (Cuvier, 1830) e Diapterus rhombeus (Cuvier, 1829) capturadas no canal de Santa Cruz, Itamaracá, Pernambuco

Abstract

This study evaluated the profiles of seasonal diets of Eugerres brasilianus and Diapterus rhombeus, and food overlap between these species caught in the channel of Santa Cruz, located on the northern coast of the Pernambuco state, from June 2010 to May 2011. The goal was to provide input as a basis for studies aimed at the sustainable use and cultivation of these species. To understand their eating habits, we analyzed 837 individuals of both species, 567 species of E. brasilianus and 270 species of D. rhombeus, which, through its degree of fullness, frequency of occurrence, frequency number and index of food importance, we could verify their diets. As for the evaluation of overlapping niches, we used the Morisita-Horn index and multivariate analysis (Euclidean Distance). The two species have a very diverse food spectrum with high niche overlap (0.97). The most consumed item by both was Polychaeta, item with more than 75% of important food for both species. Bivalvia and Decapoda, were the most consumed by E. brasilianus item after the Polychaeta, with peak consumption during the year. While, for D. rhombeus, the most consumed items after the item Polychaeta were Amphipoda and Stomatopoda. The two species, as well as most individuals Gerreidae family, can be considered generalists because they present a wide food spectrum, opportunistic taking advantage of food in abundance in the environment, and omnivores with a preference for benthic invertebrates, especially polychaetes.