12 research outputs found
Fish associated with aquatic macrophytes in the Chacororé-Sinhá Mariana Lake system and Mutum River, Pantanal of Mato Grosso, Brazil
Assemblage of fish species associated with aquatic macrophytes in Porto Murtinho Pantanal, Mato Grosso do Sul, Brazil
Longitudinal patterns of fish assemblages in mountain streams from tropical forest biome
Estimating nitrogen and phosphorus saturation point for Eichhornia crassipes (Mart.) Solms and Salvinia molesta Mitchell in mesocosms used to treating aquaculture effluent
Effects of flooding regime on the feeding activity and body condition of piscivorous fish in the Upper Paraná River floodplain
Composition and structure of fish assemblage from Passa Cinco stream, Corumbataí river sub-basin, SP, Brazil
Anthropic effects on the fish community of Ribeirão Claro, Rio Claro, SP, Brazil
The effect of anthropic alterations such as drain discharge on a fish community was studied in the Ribeirão Claro River, municipality of Rio Claro, State of São Paulo, southeastern Brazil. Samples were made monthly in three different points along the river (headwaters, mid course, and confluence) between December, 2003 and March, 2004, which is the reproductive period for the majority of the species. The fish community of the Ribeirão Claro River showed a fair composition and diversity, with species rarely observed in studies made in the region, such as Paravandellia oxyfera and Callichthys callichthys. Indices of diversity and equitability showed different results when weight or the number of individuals were considered. Moreover, these indices did not reveal the typical increase in diversity from the headwaters toward the confluence, nor the loss of richness in the part altered by drain discharge. An interpretation should be made with caution, taking into account the diverse factors included in the computation. Similar to the diversity indices, the Morisita-Horn similarity index did not reveal a great difference in the fish community of the confluence of the river, mainly in relation to its mid course. The decline of species richness and trophic composition alteration in the disturbed part is clear, which shows a great dominance of piscivorous species