Podocnemis unifilis and P. expansa are aquatic side-neck turtles, locally referred to as charapa turtles. Side-neck turtles get their name from their inability to pull their heads into their shells; instead, they bend their necks sideways to tuck their heads under their shells, leaving a part exposed. Both species lay their eggs in river sandbanks during dry season, so that the nests are not washed away.
P. expansa is the largest of all of the side-neckturtles. P. unifilis gets its name from yellow spots on its head, which are brightest in juvenile turtles. The spots eventually fade in females but remain in males.
P. unifilis and P. expansa are distributed from the Orinoco River in Venezuela and Colombia to the Amazon in Brazil, Bolivia, Ecuador and Peru. In Ecuador, charapa turtles inhabit the rivers of the Amazon in the provinces of Sucumbios, Orellana, Napo, Pastaza, and Morona Santiago.
The yellow spotted river turtle (P. unifilis) is classified as Vulnerable (VU) on the IUCN Red List and the South American river turtle (P. expansa) appears as Less Concern (LC). For both species, the main threats to conservation are increasing exploitation and marketing of their eggs for human consumption, the capture and sale of adult individuals, and habitat loss.