Summary
In this paper feeding habits and reproduction of pbout 20 species of fishes collected at igarapé do Porto, Aripuanã, MT, during the beginning of high water season, are discussed Based on the data obtained from analysis of stomach and intestinal contents, comments are made on food habits, food preferences, and distribution of the fish in the biotopes studies According to these data it was possible to situate the species in the different trophic levels recognized within each biotope. Included also are some observation concerning the breeding season of the species studies.