Trophic aspects of fish communities in Brazilian rivers and reservoirs

Abstract

Several studies about the freshwater fish communities of Brazilian river basins have been developed during the last few decades and their results have been published in scientific journals, thesis and internal reports. In this revision we surnmarise part of the information related to species richness, trophic structure and habitat use reported for streams, rivers and reservoirs. We try to identify patterns between equivalent habitats of the main river basins. Sampling explains most of the variability found between communities, but differences between streams are significantly related to latitude and differences between reservoirs are dependent on their size. The trophic structure of the communities also show common trends. Streams seem to have relatively high diversity and abundance of omnivores and insectivores, while floodplains are dominated by detritivores, and reservoirs and rivers channels have high abundances of piscivores. This structure is probably related to the productivity of the biotopes. The strategy of resource exploitation also show trends between equivalent habitats.