Diet composition for three sciaenids caught off northeastern Brazil

Larimus breviceps, Isopisthus parvipinnis, and Paralonchurus brasiliensis are the 3 most abundant species of Sciaenidae in the Marine Extractive Reserve of Corumbau in Bahia (northeastern Brazil). Ontogenetic and seasonal changes in the diet of these species were analyzed. These changes may reflect adaptations and coexistence mechanisms used by those species. Sampling took place between December 2007 and September 2008 with otter trawlers. Fishes and shrimps were the main resources consumed by these 3 species. For L. breviceps and P. brasiliensis, Sergestidae was the dominant food item (together with polychaetes for the latter) and fishes were the most important item for I. parvipinnis. Low values of niche breadth were observed for all species. The Morisita Similarity Index indicated a general pattern of low overlap between the diets of the three species analyzed in most of the seasons, with the exception of L. breviceps and I. parvipinnis, which showed values higher than 80% in all seasons, with the exception of summer. Although these species showed differences in the position and orientation of their mouth, they essentially use the same resources. The carnivorous feeding habit prevailed among the studied Sciaenidae, with predominance of the carcinophagous habit.