Grass-dominated stream sites exhibit low fish species diversity and dominance by guppies: an assessment of two tropical pasture river basins

Nenhuma Miniatura disponível

Data

2009-10-01

Autores

Casatti, Lilian [UNESP]
Ferreira, Cristiane de Paula [UNESP]
Carvalho, Fernando Rogerio

Título da Revista

ISSN da Revista

Título de Volume

Editor

Springer

Resumo

This 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.

Descrição

Palavras-chave

Habitat structure, Simplification, Riparian vegetation, Non-native species, Poecilia reticulata

Como citar

Hydrobiologia. Dordrecht: Springer, v. 632, n. 1, p. 273-283, 2009.