Food partitioning of five cyprinid fish species in Chittar River, Southern Western Ghats, India

The diet and feeding ecology of cyprinid fish species Devario aequipinnatus, Rasbora daniconius, Puntius bimaculatus, Dawkinsia filamentosa and Garra mullya were studied exploring the dietary breadth and overlaps of the species in the Chittar River, Southern Western Ghats, India. The diets of D. aequipinnatus, and R. daniconius were specialized animal matter and terrestrial arthropods whereas P. bimaculatus and D. filamentosa consumed large composition of algae and small portion of detritus respectively. Meanwhile the smaller portion of animal matter was present in the gut of P. bimaculatus while G. mullya fed on only algae and detritus with higher amount of plant matter. Levin’s index diet breadths analyses showed major overlaps between R. Daniconius and D. aequipinnatus and between G. mullya and P. bimaculatus in all the seasons. In the confluence site, generalist such as D. filamentosa and P. bimaculatus had an overlap with R. daniconius in four taxa food items and animal matter category. D. aequipinnatus and R. daniconius fall in specialist group. This D. aequipinnatus and R. daniconius species fed mainly on terrestrial arthropods from the surface. Garra mullya get a narrow feeding range in all seasons. Among co-existing species, diet overlaps were noticeably low in all seasons. Among the five cyprinids species high diet breath value and highest food overlapping was observed in the intermediate and south-west monsoon seasons. These results suggest that the diets of the fish assemblages had a distinct similarity and dissimilarity between and within surface and bottom feeding guilds. The results revealed a co-existence of five cyprinid fishes in the study area of Chittar River where a highly structured stream assemblage was observed.