Dieta da comunidade de peixes na área de influência da UHE de Balbina - rio Uatumã, Amazonas, Brasil

Abstract

This work aims to analyze temporal changes in the diet of fish species from Balbina reservoir, Uatumã River, Brazilian Amazon, by comparing data from the two periods: before and after the river was dammed. Sampling was carried out every two months, from April until October 2005, at two sites in the reservoir and two sites below the dam in the Uatumã River. One thousand stomachs from 39 fish species were analyzed using two different methods: frequency of occurrence and relative volume. The combination of the two were used to estimate alimentary index (AI). According to the AI, six trophic categories were determined: Invertivorous, Piscivorous, Detritivorous, Herbivorous, Onivorous and Lepidophaous. The majority of the species did not present spatial or temporal differences in feeding, nor between the river and reservoir environments. In the comparative analysis between the of pre-damming and post-damming no species presented significant differences between their diets.