The Family Cryptobranchidae consists of the giant salamanders, including the Chinese giant salamander (Andrias davidianus), Japanese giant salamander (Andrias japonicus), and the North American hellbender (Cryptobranchus alleganiensis). These are large, fully aquatic salamanders with flattened bodies, loose skin folds for respiration, and small eyes adapted for murky freshwater habitats. Cryptobranchids are mostly nocturnal predators, feeding on fish, insects, and other aquatic invertebrates. They exhibit external fertilization and have relatively long lifespans, often exceeding 20–30 years. As top freshwater predators, they play important roles in maintaining aquatic ecosystem balance, but many species are threatened due to habitat loss, pollution, and overharvesting.