It is the largest freshwater turtle in Southeast Asia. It has a strong head provided with strong jaws, with a slightly elongated snout. Adults have a gray or dark brown head, while young specimens have a line that runs from the mouth to the back of the head. The shell is oval and smooth, brown or black. In adults the shell has thin and smooth edges, while in juveniles it is more rounded and serrated. The plastron is pale yellow. They have an interdigital membrane on their extremities that allows them to move better in the water, and their fingers end in thin, elongated claws. The side walls of the shell form a bony cavity for the lungs, which allows the lungs to expand and withstand pressure underwater; which helps to better withstand prolonged immersions. Females deposit oval-shaped eggs with brittle shells on the banks of rivers, in nests with a base of detritus.