| Five species of Siluriformes were registered in the Ubatiba system. Pimelodella lateristriga was the dominant one, followed by Hypostomus gr. punctatus, Rineloricaria sp., Callichthys callichthys and Rhamdia sp. Simple correlation analysis between species density and habitat parameters indicated that hydrology explained density patterns of four species. Pimelodella densities were negatively correlated with pools, Callichthys and Hypostomus densities were positively correlated with runs and Rhamdia densities were positively correlated with riffles; Rineloricaria densities did not respond to any hydrological parameter. Substrata were an important factor to all species, but specific preferences were observed. Marginal vegetation was positively correlated only... |
