Composição, distribuição, utilização de ambientes e variação sazonal na densidade de quelônios aquáticos do Lago Verde, Alter do Chão, Santarém, Pará, Brasil

Abstract

The Amazon basin is home to 16 species of freshwater turtles. Most studies of these animals are conducted in the region are based on reproductive aspects, few studies have focused on the abundance, the use of environment and population structure. We studied the spatial distribution, the use of environment and seasonal variation in the density of five species of aquatic turtles Green Lake in Santarém, Pará, Brazil (Podocnemis expansa, P. erythrocephala, P. unifilis, dumerilianus Peltocephalus and Phrynops tuberosus) over the period between December 2008 and November 2009. the animals were spotted and captured by assoalhando animal counts and dives. Most of the animals found in the flooded forest environments (n = 64; 66%), mainly in igapó aningal (Montrichardia sp) and mixed igapó except Phrynops tuberosus, a species that was captured mostly along the lakeshore . The highest densities were recorded in hydrological station of the flood during the rising water levels, with no catches in samples taken during the dry period, with only one individual seen in December (P. unifilis). No relationship was found between the density of spotted animals and the quota of the Tapajós River. There was no change in the sex ratio of the species recorded between environments of Green Lake. The distribution maps of individuals in different phases of the hydrological cycle indicate a clear trend advance into the igapó in that the water level rises and overflows this environment. The flooded lands, especially those harboring aninga agglomerations are critical environments for aquatic turtles in the study area, recommending to protect these areas for the conservation of Green Lake aquatic turtles community.