Food Habits of an Assemblage of Five Species of Turtles in the Rio Guapore, Rondonia, Brazil

Abstract

The feeding habits of five species of turtles were studied from June-November 1989 and March-June 1990 in the Guapore River and its tributaries (San Domingos and San Miguel) in Costa Marques, Rondonia, Brazil. Turtles were captured using unbaited fyke nets. Stomach contents were flushed from Podocnemis unifilis (N = 351), Podocnemis expansa (N = 3), Phrynops geoffroanus (N = 31), Phrynops raniceps (N = 5), and Chelus fimbriatus (N = 5). We found no seasonal differences in food consumed by P. unifilis; however, differences were found between the sexes. Females consumed more seeds and fruits, whereas males consumed more shoots and stems. Consumption of seeds and fruits increased linearly as a function of the mean carapace length of P. unifilis, whereas the consumption of fish eaten decreased with increase in mean CL. Seeds and fruits were consumed at higher frequency and volume in flooded forest than in lakes and rivers. We found no difference in types of food consumed between habitats or sexes in P. geoffroanus. Adult Gerridae, Libellulidae larvae, and crustaceans of the family Palaemonidae occurred in high numbers in the stomach contents of P. geoffroanus when water levels were falling, whereas only fruits of Myrtaceae and Sapotaceae were found during the season of rising water levels. Podocnemis expansa consumed primarily plant material, and P. raniceps fed predominantly on Gastropods. Chelus fed on the fish Cren- icichla (Cichlidae) and Triportheus (Characidae).