Feeding ecology, density and biomass of the freshwater turtle, Phrynops geoffroanus, inhabiting a polluted urban river in south-eastern Brazil

This study examines the ecology of a population of Geoffroy's side-necked t urtle Phrynops geoffroanus inhabiting a polluted urban river in Ribeirao Pr eto city, Sao Paulo state, south-eastern Brazil. Adult turtles fed mainly o n Chironomidae larvae and pupae (Chironomus cf. plumosus, 100% of occurrenc e frequency) and domestic waste, but they also consumed terrestrial items ( cockroach, snails) and carrion. Juvenile turtles showed more feeding divers ity than the adults and exhibited a trend for predation on Chironomidae pup ae, but this is not reflected in resource partitioning. The elevated number of turtles (170-230 turtles/ha of river) and biomass (255-345 kg/ha of riv er) inhabiting this urban river is probably the result of the abundance of sewage and organic waste produced by humans, the absence of predators, and increased availability of nesting areas. Such factors convert this area int o an environment highly advantageous for the survival of Geoffroy's side-ne cked turtle.