Habitat use by two species of Hypostomus (Pisces, Loricariidae) in southeastern brazilian streams

In this study, habitat use of the armored catfishes Hypostomus ancistroides and Hypostomus sp. was investigated in 21 streams from the Upper Rio Paraná system in São Paulo State, Brazil, a pasture dominated region. The abundance of Hypostomus sp. was positively correlated with the amount of riffles and riparian vegetation condition, whereas H. ancistroides abundance was negatively correlated with riparian vegetation condition. Thirteen ecomorphological attributes analyzed by principal component analysis showed that when compared to H. ancistroides, Hypostomus sp. presented a wider mouth and more flattened body, suggesting an adapted body to faster waters. The most abundant populations of Hypostomus sp. were predominantly associated with good riffle availability and good riparian quality, suggesting that populational features of this species may be incorporated in the stream biotic integrity assessment in that region.

armored catfishes; upper Rio Paraná; ecomorphology; diet; habitat partitioning