Structure of a benthic macro invertebrates community in a mountain stream in Itatinga, Sao Paulo, Brazil

The benthic macroinvertebrates community of a third order stream was studied during the wet and dry seasons. The community was analyzed using artificial substrates sampled weekly during 56 days in each season. The community composition was characterized by low species diversity, with high 'number of rare species and few abundant species for both seasons. A high dominance of Chinonomidae (Diptera) for both seasons, followed by Baetidae (Ephemeroptera) and Ancylidae (Mollusca), respectively for the wet and dry seasons, was found. The results reinforced the high importance of Chironomidae and the seasonal effect determining the stream benthic community structure.