Gradientes de diversidade nas comunidades de peixes da bacia do rio Iguatemi, Mato Grosso do Sul, Brasil

Abstract

ABSTRACT. Diversity gradients in fish communities of Iguatemi river basin, Mato Grosso do Sul, Brazil. In order to verify the importance of longitudinal and seasonal variations and the effect of physical and chemical water characteristics to fish species diversity we accomplished three-month samplings, between November/1999 and August/2000, in three selected points in the Jogui River and eight points in the Iguatemi River-MS. The longitudinal variation was more important than seasonal variation in determining richness and number of individuals in the Jogui River, however, evenness did not present statistically significant differences either longitudinal or seasonal. In the Jogui River 78.3% of species richness, 81.6% of number of individuals and 41.1% of evenness variation was explained by the water chemical and physical characteristics. In the Iguatemi River we did not detect longitudinal or seasonal statistically significant differences in the analyzed community descriptors nor significant influence of environmental factors.

Ichthyofauna from three streams of the lower Iguatemi River in the upper Paraná river basin, Brazil

“…The greatest number of accessory and occasional species recorded in Água Boa and Santa Maria suggests a high exchange of species between these streams and Iguatemi River, as long as fish may use these environments in the search for resources. Súarez and Petrere-Júnior (2006) drew similar inferences for Jogui region, Iguatemi river basin and Viana et al (2013) for Bonito region, Ivaí river basin.…”

Environmental factors predicting fish community structure in two neotropical rivers in Brazil

“…The existing studies were carried out in the lower portion of the Ivinhema basin, with regard to the Paraná River floodplain (Agostinho et al, 2000;Petry et al, 2003 a, b). For the Iguatemi River basin, studies have examined fish species associations, stream fish communities, and variations in fish diversity (Súarez et al, 2003(Súarez et al, , 2005(Súarez et al, and 2006.…”

Bacias hidrográficas como unidades de variação geográfica e de conservação de vertebrados

“…Somente duas regiões da bacia hidrográfica do Rio do Peixe tiveram registros de ictiofauna e não possuem uma diferença significativa na sua composição de espécies. Tal fato é diverso daquele observado em outras bacias hidrográficas, em que é comum encontrar diferenças entre áreas amostrais distintas (SÚAREZ & PETRERE-JÚNIOR, 2006;SÚAREZ & LIMA-JÚNIOR, 2009;HIRSCHMANN, 2015). No entanto é possível considerar que, em alguns rios, não há diferença nos índices de diversidade entre as áreas amostrais, apenas na composição de espécies (SÚAREZ & PETRERE-JÚNIOR, 2003.…”