Distribution: Southeastern United States. Size: It is the largest freshwater turtle in the world. It can grow up to 30 in. (75 cm) and weigh up to 176 lbs. (80 kg). Their tails are about as long as their shells. Males are typically larger than females. Habitat and Diet: They spend most of their lives in the deep waters of rivers, lakes, canals, swamps and bayous. At night, they prey upon fish, snakes, frogs, aquatic plants, clams and other turtles.