Feeding habit and food partitioning in a stream fish community of Western Ghats, India

The diet and feeding ecology of 12 cyprinid fishes were studied in the Thalayanai stream of southern India. The diet of Barbodes sarana, Danio aequipinnatus and Rasbora daniconius were specialized in terrestrial and aquatic insects. Hypselobarbus dobsoni and Garra mullya consumed vegetative matter and unicellular algae as their most important dietary component, respectively. Hypselobarbus curmuca and Hypselobarbus dubius specialized in crustaceans and molluscs. Puntius amphibious, Puntius bimaculatus, Puntius dorsalis, Puntius filamentosus and Puntius tambraparniei fed on variety of food resources (aquatic insects, algae and detritus) and their feeding intake varied between wet to dry seasons. Levin's index of diet breadth showed the broadest diets for P. dorsalis in both seasons, whereas G. mullya had a narrow feeding spectrum in both seasons. Among co-existing species, diet overlaps were substantially low during both wet and dry season. These results suggest that feeding specialization and low diet overlap reduce inter-specific competition, allowing co-existence of these cyprinid fishes in this highly structured stream assemblage.