The Cryptobranchidae are a family of salamanders 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), reaches up to 1.44 m (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 m (5.9 ft)
Cryptobranchids are large salamanders, with large folds of skin along their flanks. These help increase the animals' surface area, allowing
them to absorb more oxygen from the water. They have four toes on the fore limbs, and five on the hind limbs.Their metamorphosis from the
larval stage is incomplete,so the adults retain gill slits (although they also have lungs), and lack eyelids.
The Japanese giant salamander has lived for as long as 52 years in captivity.