Population and biological parameters of selected fish species from the middle Xingu River, Amazon Basin

Parâmetros biológicos e populacionais de peixes do meio Rio Xingu, Bacia Amazônica

Abstract

This study estimates the main biological parameters, including growth rates, asymptotic length, mortality, consumption by biomass, biological yield, and biomass, for the most abundant fish species found on the middle Xingu River, prior to the construction of the Belo Monte Dam. The specimens collected in experimental catches were analysed with empirical equations and length-based FISAT methods. For the 63 fish species studied, high growth rates (K) and high natural mortality (M) were related to early sexual maturation and low longevity. The predominance of species with short life cycles and a reduced number of age classes, determines high rates of stock turnover, which indicates high productivity for fisheries, and a low risk of overfishing.

Keywords:
amazon fishes; population dynamics; life history strategies; Belo Monte dam