The Arrau turtle
, also known as the Arrau River Turtle
, is the largest of the side-neck turtles
. Females have wide flattened shells and are larger and more numerous than the males. Adult Arraus feed entirely on plant food. The nesting habits of this species are similar to those of their sea turtle kindred. Like sea turtles they gather in huge numbers in order to travel to suitable nesting areas. The females lay their eggs on sandbanks which are exposed only in the dry season, and there are relatively few such sites. The females come out on the sandbanks at night to lay their eggs which can number anywhere from 90 to 100 soft-shelled eggs. They then return to their feeding grounds. The young when hatched are around 2 in long dart directly for the water, but they emerge to the attentions of many predators and even without man's activities, only about five percent ever reach the adult feeding grounds. Because of this it is a endangered species and is protected in most areas.