Chironomidae (Diptera) em substratos artificiais num pequeno reservatório: Represa do Monjolinho, S？o Carlos, S？o Paulo, Brasil

the present study aimed to verify possible taxonomic and functional differences between the chironomidae assemblages that colonize organic and inorganic substrates of different structures. polymers (polystyrene and nylon mesh), minerals (pyro clay and sand) and organic vegetable substrates (wood branches and litter of scirpus cubensis and cabomba piauhyensis) were immersed in monjolinho reservoir water column in nylon mesh bags. after 30 days, they were taken and washed through a 0.21 mm mesh sieve. the organisms retained by the sieve were identified under stereoscopic and/or optic microscopes. the 3432 larvae analyzed pointed to the presence of 17 taxonomic units. goeldichironomus neopictus was the predominant species, colonizing abundantly all the substrates (>73%). the quantitative (euclidean distance) and qualitative (jaccard coefficient) cluster analyses pointed to different groups. the former grouped the assemblages that had colonized sand and wood branches (substrates with the greatest numeric densities and richness), polymeric substrates (polystyrene and nylon mesh) and macrophyte litters. jaccard coefficient pointed to the greatest similarity of the assemblages present on organic vegetable and on mineral substrates. on the other hand, the assemblages were functionally similar because of the high participation of collectors on all the substrates (>95%).