Fossils indicate that Cryptobranchus formerly occurred also in western North America. Asian salamanders of the genus Andrias are used for food and are now considered highly endangered. These large, aquatic salamanders have dorsoventrally flattened bodies except on the tail, which is laterally compressed and finlike. Limbs are short but massive and sturdy. Folds are present in the skin, which forms flaps along the lateral margins of the body.
Eyes are small and lack eyelids.
Larvae have caudal fins and short, external gills. They live under rocks on the bottoms of fast-flowing streams and rivers. The morphological characters given below are the ones standardly used to diagnose the salamander family Cryptobranchidae and to assess its phylogenetic relationships to other salamanders. The individual characteristics are in most cases shared with other salamanders and should not be interpreted as synapomorphies of the Cryptobranchidae. Metamorphosis is incomplete in the Cryptobranchidae, leading to a number of paedomorphic characteristics in adults.