Summary
Studies of the food and feeding habits of the three species of Anostomidae most common in the "white waters" near Manaus, Schizodon fasciatus, Rhytiodus microlepis e R. argenteofuscus are presented. Data were analysed with respect to the stage of development of the fish and the regional water levels at the time of capture. The three species are herbivorous with certain degrees of preference determined by the type and structure of the vegetation ingested. There is possibly a relationship between the nature of the food ingested, the ambient conditions and certain characteristics of the digestive tract.