Invertebrates community composition from a tropical stream and its spacial and tempo¬ral variation

Abstract

The distribution pattern of aquatic organisms results from the interaction of the habit, the physical conditions of the habitat (substrate, flow. turbulence), and the food availability. The purpose of this study is to know the composition and understand the distribution pattern of the animal community of a tropical stream. Two stretches consecutives of one ufluent in Parenapanema Basin, located in the city of Itatinga (SP) were chosen. One of the stretches is bordered by riparian vegetation (closed area) and the other is bordered only by shrub vegetation, with branches pending over the water (open area). The influence of factors, as season (dry and wet), area (closed and open), stretch (riffle and pool), upon the distribution of aquatic macroinvertebrates of the Córrego ltaúna was analysed. lnsects were the taxa of invertebrates that prcdominated. The macroinvertebrates were predominant in the Open area, in stretches of rifIles, and in the dry season.