Cryptobranchidae is a family of salamander commonly known as the Giant Salamanders. A single species, the hellbender (Cryptobranchus alleganiensis) occurs in the eastern United States, while Asian species occur in both China and Japan.
They are the largest living amphibians known today. The Japanese giant salamander (Andrias japonicus), for example, reaches up to 1.44 metres (4.7 ft), feeds on fish and crustaceans, and has been known to live for more than 50 years in captivity. The Chinese giant salamander (Andrias davidianus) can reach a length of 1.8 metres (5.9 ft)
Cryptobranchids are large, corpulent salamanders, with large folds of skin along their flanks. These help increase the animal's surface area, allowing them to absorb more oxygen from the water. They have four toes on the forelimbs, and five on the hind limbs. Their metamorphosis from the larval stage is incomplete, so that the adults retain gill slits (although they also have lungs), and lack eyelids. They can reach a static size of 2 meters (6 feet 6 inches) in length. They weigh up to 145 lbs. Chinese Giant Salamanders have lived as long as 75 years in captivity. The Chinese giant salamander eats aquatic insects, fish, frogs and also crabs and shrimp.