Perfil e variação energética de filhotes de tartarugas-da-amazônia (Podocnemis expansa) e tracajás (Podocnemis unifilis) mantidos em condição de berçário, sob diferentes sistemas de alimentação

Abstract

The use of turtles in the Amazon region is ancient, and began with local people, but alarmingly increases with the european colonization. The use as food and its fat for public lighting, as well as the indiscriminate predation of its eggs generated important impacts on their population. The Pé-de-pincha Project was created in 1999, with the objective of protecting and increasing the populations of Amazonian podocnemidids, the Giant river turtle (Podocnemis expansa) Yellow spotted river turtle (Podocnemis unifilis). For this purpose, they created a community management bases, in nest beaches throughout the states of Amazonas and Pará, aiming to protect nests and hatchlings, increasing their survival through headstarting. Strategies like that are used around the world, but still generate some criticism about their effectiveness. The objective of this study was to evaluate the use of residual yolk in hatchlings over 60 days and the variation in locomotor performance throughout the maintenance period in captivity, under laboratory and hatchery conditions, as well as bromatological variations and serum biochemical index. For this purpose, ten giant river turtle nests and ten yellow spotted river turtle nests were used, five natural nests and five translocated nests of each species. Two experiments were set up, one in the laboratory, evaluating the performance in animals kept with daily feeding (simulating hatchery) and without feeding (simulating wild). Another experiment evaluated the variables in a hatchery system, similar to ribeirinhos method used in the Pé-de-Pincha Project. It was verified that the residual yolk of the hatchlings is almost totally consumed over 60 days, but feeding strategy does not influence this consumption, but positively influences its growing, wich animals fed being larger than the others. P. expansa grows more than P. unifilis, and maintain better locomotor skills throughout development. Captivity maintance tend to decreases the hatchlings running ability, but not self-righting or swimming performance. Bromatological and calorimetric data indicate that the hatchlings didn´t lost energy, their energy values remain constant over time, indicating a transfer of energy, especially triglycerides, from the residual yolk to the carcass of the individuals. The data obtained allow us to infer that the maintenance of hatchlings in a headstarting system does not negatively impact their energy metabolism neither reserves, nor locomotor performance, as well as ensures releasing larger animals, reducing their predation in the wild.