Diet and feeding activity of Acestrorhynchus lacustris (Lütken, 1875) (Characiformes, Acestrorhynchidae) in the water reservoir at Ribeirão Claro, SP.

A. lacustris is a widely distributed species in the São Francisco and Paraná river basins, mainly in lentic waters. Specimens were captured monthly, over a whole year in a reservoir built by damming the Ribeirão Claro stream (SP). The stomach contents analyses showed a predominantly piscivorous diet. Feeding activity showed to be clearly less intense during winter, when all the sampling groups were compared. Despite the fact that the diet of A. lacustris presents a high diversity of prey-species, the prey size, their abundance and also behavior possibly determined a certain preference for some of them.