SPATIAL AND SEASONAL VARIATION OF THE BENTHIC MACROINVERTEBRATES DIVERSITY IN TWO HEADWATER STREAMS, TIETÊ RIVER BASIN, MUNICIPALITY OF JAÚ, SP

Abstract

The benthic macroinvertebrates are a diverse group of great ecological importance in stream ecosystems, participating in the energy flow and nutrient cycling, and as the link between basal resources (detritus and algae) and fish. In this work two first order streams of Tietê River basin will be studied on benthic macroinvertebrate diversity and possible spatial and seasonal variations in the composition according to the characteristics of the environment. The streams are located in the Ecological Reserve RPPN Amadeu Botelho (REAB), in the Santo Antonio dos Ipês's farm, at Jau municipality, central-west region of São Paulo. In March (rainy season) and July (dry season) of 2012, environmental analysis and the benthic community sampling will be performed. The invertebrates will be sampled with Surber sampler (250m¼ mesh), in different types of substrates (sand, gravel, plant debris) in a total of nine replicates per stream and season. The composition of this fauna will also be analyzed using the information of the local ichthyofauna'diet, verifying the adequacy of this methodology as a complementary tool for characterizing the composition and spatial and temporal distribution of benthic macrofauna.