Composição e estrutura das assembleias de peixes de riachos da bacia do Rio de Contas, Bahia, Brasil

• Autor(a) principal: Silva, André Teixeira da [UNESP]
• Data de Publicação: 2015
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: Repositório Institucional da UNESP
• Texto Completo: http://hdl.handle.net/11449/154654; http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/26-04-2018/000898322.pdf
• topic: Peixe; Ictiofauna; Caatinga; Fishes; Bahia; Mata Atlântica; Diamantina, Chapada (BA); Contas, Rio de (BA)

The Contas river basin lies completely inside the Northeastern Mata Atlântica freshwater ecoregion, and though it may be recognized as one of the main hydrographic systems of the ecoregion its ictiofauna knowledge lacks much information. For being under the influence of biomes Caatinga and Atlantic Forest, it was possible to assess the role of environmental factors acting at different scales in the organization of stream fish assemblages. Therefore, in Chapter 1 were evaluated the composition of the fish fauna streams in three sub basins Alto Contas that represent the Chapada Diamantina region, the Gavião river sub basin that represent the Caatinga region, and finally the Gongogi river sub basin representing the Atlantic Forest region. In Chapter 2 it was verified the importance of local and regional environmental variables and spatial variables on the taxonomic and functional organization of stream fish assemblage belonging to Gongogi river and Alto Contas sub basins. The Contas basin streams exhibited a fish fauna with 50 species, with eight endemic species of the basin. The three sub basins fish compositions and species richness differed, which were higher on Gongogi river sub basin. Separately local environmental variables, regional and space significantly explain the taxonomic and functional structure of the fish assemblage. However, the combined effect was more relevant explaining important portions of variation in assemblies. The results suggest that the Contas basin displays a taxonomic compartmentation of the fish community, especially due to distinct biogeographic history and limitation of dispersion among the sub-basins, with a relative importance of regional variables. Moreover, the functional structure was mainly structured due to the combination of local environmental filters related to regional environmental factors, and small scale spatial variables