I thought they were apex predators as adults, but all turtle hatchlings are subject to predation. I couldn`t recall if the Amazon had snappers. Just read that South America does, though. So probably. 

From Wiki:

Common snapping turtles have few predators when older, but eggs are subject to predation by crows, mink, skunks, foxes, and raccoons. As hatchlings and juveniles, most of the same predators will attack them as well asherons (mostly great blue herons), bitterns, hawks, owls, fishers, bullfrogs, large fish, and snakes.