Dieta de duas espécies de peixes do Ribeirão do Atalho, Itatinga, SP
ResumoThe diet and niche breadth of two fish species, Astyanax
scabripinnis Eigenmann, 1914 (Characidae, Tetragonopterinae) and Characidium schubarti (Travassos, 1964) (Crenuchidae, Characidiinae) were studied in a tropical stream, in the wet and dry seasons. The major food item exploited by those fishes was aquatic insects, mainly Diptera-Chironomidae. Both species presented a significant seasonal and ontogenetic variation in diet what showed their flexibility for the exploration of the food resources available in this environment. Besides, the two species presented an opportunistic diet, ingesting mainly the most abundant food items. The values of niche breadth near 0.5, similar for both species, reinforced their generalist diet, in spite of a tendency to omnivory for A. scabripinnis and to carnivory for C. schubarti.