Biologia de Trachemys adiutrix (Vanzolini, 1995) (Testudines, Emydidae) no litoral do Nordeste-Brasil

Abstract

In the period of June 2005 and May 2006, we have studied parameters of the biology, population dynamics and distribution of the fresh water turtles Trachemys adiutrix (TESTUDINES, EMYDIDAE), in the coast of the States of Maranhão and Piauí. T. adiutrix is aquatic and lives both in perennial and intermittent fresh water lakes. Five common names are employed in the occurrence area: cágado, juraraca, jurará, pininga e capininga. In the Lençóis Maranhenses, Pequenos Lençóis Maranhenses and Delta do Parnaíba Islands, T. adiutrix seeks terrestrial shelter on the dry season (aestivation). This inactivity period may last for seven months (July to February). The sexual ratio of the monitored population was 1:1.30 for males (n=140) which was not statistically significant (x2 = 0.60; p > 0.05). The density found was 0.010 turtles per ha and the biomass was 0.005 kg/ha. We registered the occurrence of T. adiutrix in 25 localities of 11 municipalities, two of them in the State of Piauí and nine in the State of Maranhão. The male and female plastron length differences were statistically significant (ANOVA; F = 81.21; p = < 0.0001; n = 114). Both turtle populations are opportunistic omnivorous and there was no superposition of feeding niche between juveniles and adults, but for males and females.