The Chinese giant salamander (Andrias davidianus) is one of the largest salamanders and one of the largest amphibians in the world. It is fully aquatic, and is endemic to rocky mountain streams and lakes in the Yangtze river basin of central China. Either it or a close relative has been introduced to Kyoto Prefecture in Japan and to Taiwan. It is considered critically endangered in the wild due to habitat loss, pollution, and overcollection, as it is considered a delicacy and used in traditional Chinese medicine. On farms in central China, it is extensively farmed and sometimes bred, although many of the salamanders on the farms are caught in the wild. It has been listed as one of the top-10 "focal species" in 2008 by the Evolutionarily Distinct and Globally Endangered project. The Chinese giant salamander is considered to be a "living fossil". Although protected under Chinese law and CITES Appendix I, the wild population has declined by more than an estimated 80% since the 1950s. Although traditionally recognized as one of two living species of Andrias salamander in Asia, the other being the Japanese giant salamander, evidence indicates that the Chinese giant salamander may be composed of at least five cryptic species, further compounding each individual species' endangerment. Taxonomy The correct scientific name of this species has been argued to be Andrias scheuchzeri (in which case Andrias davidianus would be a junior synonym) – a name otherwise restricted to an extinct species described from Swiss fossils. It has also been given the moniker of "living fossil" for being part of the family Cryptobranchidae which dates back 170 million years. It is one of only five to six known extant species of the family, the others being the slightly smaller, but otherwise very similar Japanese giant salamander (Andrias japonicus), the slightly larger South China giant salamander (A. sligoi), the Jiangxi giant salamander (Andrias jiangxiensis), an undescribed Andrias species from eastern China, and the far smaller North American hellbender (Cryptobranchus alleganiensis). A 2018 study of mitochondrial DNA revealed that there are five wild clades of the Chinese giant salamander, as well as two only known from captives (their possible wild range was previously unknown). They diverged from each other 4.71–10.25 million years ago and should possibly be recognized as cryptic species. Despite this deep divergence, they can hybridize among each other, and also with the Japanese giant salamander. One of these