Casatti, Lilian [UNESP]Ferreira, Cristiane de Paula [UNESP]Carvalho, Fernando Rogerio2014-05-202014-05-202009-10-01Hydrobiologia. Dordrecht: Springer, v. 632, n. 1, p. 273-283, 2009.0018-8158http://hdl.handle.net/11449/22416This study investigates whether (1) structural configuration (considering substrate composition, wood debris, marginal and riparian vegetation) of streams suggests habitat simplification on a basin scale and (2) fish assemblage structure follows stream habitat configurations. Ninety-five sites in two pasture basins in southeastern Brazil were randomly selected. Two passes of electro-fishing were done in a 75-m reach at each site. Ten habitat descriptors related to in-stream and riparian physical structures were evaluated at each stream reach. Two groups of streams were identified by principal component analysis: a grassy and a non-grassy group. In comparison to non-grassy sites, grass-dominated streams exhibited a more homogenous fish fauna due to lower species diversity and higher dominance, especially by the guppy Poecilia reticulata, a highly generalist exotic species. The grassy group had not only the most simplified habitat but also the most simplified fish fauna, and the combination of grass-dominated, completely deforested, heavily silted conditions with recent land use conversion may cause a future habitat homogenization followed by a fish fauna homogenization on a regional scale.273-283engHabitat structureSimplificationRiparian vegetationNon-native speciesPoecilia reticulataArtigo10.1007/s10750-009-9849-yWOS:000268728500019Acesso restrito8041011456158217