[Diet of the tropical freshwater fish Heterandria bimaculata (Haeckel) and Poecilia sphenops Valenciennes (Cyprinidontiformes: Poeciliidae)].

We analyzed the diet and feeding habits of the fishes Heterandria bimaculata and Poecilia sphenops. Specimens were captured monthly in "Los Carros" damp, Morelos, Mexico (18 degrees 37' N, 98 degrees 43' W). We quantified gut content by the numerical method and by the frequency of occurrence method; and used the MacArthur and Levin's indices for niche overlap.