Ecological aspects of a population of Phrynops geoffroanus (Schweigger, 1812) in a semi-arid area of Northeastern Brazil

Phrynops geoffroanus is a testudine of the family Chelidae that has wide distribution. However, there are gaps in knowledge its biology. This study aimed to characterize demographically and morphometrically population an ephemeral water reservoir semi-arid area Paraíba, period from April 2016 March 2017. The individuals were captured manually by hoop-net trap. Data on size distribution described mean standard deviation. Size weight compared between sexes capture methods using MANOVA. Sex ratio was Pearson's chi-squared test. Population density biomass calculated. number animals grouped into two shifts compared. Throughout year, 113 P. reservoir, with 43.4% males, 47.8% females 8.8% juveniles, at least 41.8 / ha 33.05kg ha. There no significant relationship amount rainfall during sampled. Due mainly ephemerality aquatic environments Caatinga unpredictability this biome, populations species show large variations their biological activities. Further studies needed fill several natural history testudines.