Fish, lower Ivinhema River basin streams, state of Mato Grosso do Sul, Brazil

The Ivinhema River basin is one of the main tributaries of the western portion of Paraná River. However,few data are available on the fish communities of its streams. Monthly samples were made in seven streams of the lower portion of the basin, in the state of Mato Grosso do Sul, using a rectangular sieve 1.2 x 0.8 m, with 2 mm mesh size. Forty-six fish species were found in these streams. The richness estimated according to the bootstrap procedure was 50 species. At least two of the captured species were not previously recorded for the upper Paraná basin, indicating the need of new sampling effort in this region.