, Volume 632, Issue 1, pp 273–283

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

  • Lilian Casatti
  • Cristiane de Paula Ferreira
  • Fernando Rogério Carvalho
Primary research paper

DOI: 10.1007/s10750-009-9849-y

Cite this article as:
Casatti, L., de Paula Ferreira, C. & Carvalho, F.R. Hydrobiologia (2009) 632: 273. doi:10.1007/s10750-009-9849-y


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.


Habitat structure Simplification Riparian vegetation Non-native species Poecilia reticulata 

Supplementary material

10750_2009_9849_MOESM1_ESM.doc (89 kb)
Supplementary material 1 (DOC 89 kb)

Copyright information

© Springer Science+Business Media B.V. 2009

Authors and Affiliations

  • Lilian Casatti
    • 1
  • Cristiane de Paula Ferreira
    • 1
  • Fernando Rogério Carvalho
    • 2
  1. 1.Laboratório de Ictiologia, Departamento de Zoologia e Botânica, IBILCEUNESP-Universidade Estadual PaulistaSao Jose do Rio PretoBrazil
  2. 2.Laboratório de Ictiologia, Departamento de Zoologia e Programa de Pós-Graduação em Biologia Animal, Instituto de BiociênciasUFRGS-Universidade Federal do Rio Grande do SulPorto AlegreBrazil

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