Alimentação e digestibilidade em filhotes de irapuca (Podocnemis erythrocephala Spix, 1824)

Abstract

The red-headed Amazon river turtle (Podocnemis erythrocephala) is an Amazonian freshwater turtle primarily associated with blackwater environments of the Rio Negro basin, whose conservation and captive management are limited by scarce information on its nutritional requirements and digestive physiology. This thesis evaluated scientific knowledge, nutrition, growth, and feed utilization in the species by integrating a bibliometric analysis with experimental trials using hatchlings and juveniles maintained in captivity. Different dietary crude protein and energy levels, gastrointestinal transit time, and apparent digestibility of corn and soybean meal were evaluated. The bibliometric analysis revealed limited scientific production and knowledge gaps related to the nutrition and management of the species. Dietary protein levels affected growth, with better performance at intermediate concentrations, whereas gross energy levels ranging from 3,200 to 3,900 kcal/kg did not significantly affect juvenile performance. Gastrointestinal transit was prolonged, with complete fecal marking occurring between 18.25 and 19.75 days and all experimental units reaching maximum fecal coloration by day 22. Corn and soybean meal showed high apparent digestibility coefficients for dry matter and crude protein, exceeding 96%, indicating high nutrient utilization. Overall, these findings expand current knowledge of the nutrition and digestive physiology of P. erythrocephala and provide species-specific parameters that may support diet formulation, feeding management, captive maintenance, and conservation strategies for this Amazonian freshwater turtle.