Japanese giant salamander  (Andrias japonicus)

The Japanese giant salamander is classified as Near Threatened (NT) on the IUCN Red List (1), and listed on Appendix I of CITES (4).

The Japanese giant salamander (Andrias japonicus) is the second largest salamander in the world, growing in length to a massive 1.5 metres (2). The largest is the Chinese giant salamander, which grows to 1.8 metres while most other salamanders are only 5 to 15 centimetres in length. The Japanese giant salamander 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 Japanese giant salamander with poor vision. It is however well adapted to its aquatic life (5).

The Japanese giant salamander occurs in the rivers of northern Kyushu Island and western Honshu in Japan (3).

The Japanese giant salamander inhabits cold, fast flowing freshwater mountain streams and rivers (3).

The Japanese giant salamander is generally active at night, when it relies on smell and touch to locate its prey. This giant amphibian 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, the Japanese giant 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 in the Japanese giant salamander 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).

The Japanese giant salamander 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).

View information on this species at the UNEP World Conservation Monitoring Centre.

For more information on the Japanese giant salamander see:

• BBC Wildlife Finder:
  http://www.bbc.co.uk/nature/species/Japanese_giant_salamander
• Halliday, T. and Adler, K. (2002) The New Encyclopedia of Reptiles and Amphibians. Oxford University Press, Oxford.