Japanese giant salamander  (Andrias japonicus)

The Japanese giant salamander is the second largest salamander in the world, growing in length to a massive 1.5 meters (2). The largest is the Chinese giant salamander, which grows to 1.8 meters while most other salamanders are only 5–15 centimetres in length. The Japanese species is huge and fairly ugly in appearance, though totally harmless. Its skin is a mottled grey, black and cream, and heavily wrinkled (5). This species has an elongated body, a long broad tail and two pairs of legs that are roughly similar in size. The eyes are tiny and positioned on top of the broad, flat head, providing the salamander with poor vision. It is however well adapted to its aquatic life (5).

Occurs in the rivers of northern Kyushu Island and western Honshu in Japan (3).

Inhabits cold, fast flowing freshwater mountain streams and rivers (3).

This giant amphibian is generally active at night, when it relies on smell and touch to locate its prey. It feeds on a variety of prey, including fish, smaller salamanders, worms, insects, crayfish and snails: catching them with a rapid sideways snap of the mouth (4) (5). It has an extremely slow metabolism and can go for weeks without eating if necessary (3). During the day it retires beneath rocks (4).

Like other amphibians, this salamander has smooth skin rather than scales. The skin acts as a respiratory surface, where oxygen enters the body and carbon dioxide is released (4). This species' large size and lack of gills are thought to confine them to cold, fast flowing water where oxygen is in good supply (4).

Reproduction takes place in late August, when hundreds of individuals congregate at nest sites. Males compete viciously, with many dying from injuries. Females lay between 400 and 500 eggs in the nest, held together like a thread of beads (3). Several males fertilise the eggs, and protect them from predators like fish, until they hatch 12-15 weeks later in the early spring (5).

This species is threatened by hunting, as its flesh is a delicacy in Asia. A more recent and worrying threat is the silting up of rivers in Japan where it is found, due to deforestation creating soil erosion and runoff (3).

The Japanese giant salamander is now protected from international trade by its listing on Appendix I of the Convention of International Trade of Endangered Species (CITES) which hopefully will reduce the hunting threat facing this animal (4). Conservation efforts to reforest and protect this ancient species' habitat are also essential for the survival of this species (3).

For more information on the Japanese giant salamander see:

Hallidy, T. Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.

This information is awaiting authentication by a species expert, and will be updated as soon as possible. If you are able to help please contact:
arkive@wildscreen.org.uk