Freshwater turtles have shells that protect their bodies and come in many shapes and sizes. Some turtle species are endangered. Turtles have claws and webbed feet to help them swim. They breathe air and live both on land and in water. Female turtles choose their mates and lay eggs without help from males. The largest freshwater turtle is the alligator snapping turtle and the smallest is the bog turtle. Some turtles make interesting pets.