Japanese Giant Salamander

Japanese Giant Salamander
オオサンショウウオ
Character Data
Romaji		Ōsanshō̄o
Debut		Kemono Friends (2015 Game)
Animal Data
Scientific Name		Andrias japonicus
Distribution		southwestern Japan
Diet		Carnivore
Avg. Lifespan		?
Read More		Japanese giant salamander
Conservation

Japanese Giant Salamander​

Nexon Game

Japanese Giant Salamander is a type of Friend that appeared in the original Kemono Friends mobile game.

Series Appearances

Appearances In Kemono Friends Media

Media		Role

In Real Life

The Japanese Giant Salamander is endemic to Japan, where it is found in the Chubu, Kinki and Chugoku regions of central and western Honshu, in Shikoku and in northeastern Kyushu. The salamander occurs in habitats ranging from relatively large rivers (20-50 m wide) to small tributary streams (1-4 m wide), with clear cool water flowing through granite and schist regions. These streams have usually rocky or gravel bottoms, and at places shallow, quietly running water. The animals keep themselves concealed in rocky caverns or in burrows on the water’s edge. Vertical distribution 300 to 1000 m. Spawning nests and larvae often occur in relatively small lotic habitats, including the upper reaches of tributary streams.

Spawning occurs in late August to early September. Eggs are deposited in long strings, containing 400-600 eggs. Diameter of egg 5 mm; diameter of external gelatinous capsule 8 to 15 mm. At water temperatures between 8° and 18° C embryonic development takes 40 to 60 days. Larvae hatch in October-November at a total length of 30 mm and start feeding after absorption of yolk. One year old larvae measure about 100 mm, three year olds some 200 mm. At this size larvae start losing their gills. Males reach sexual maturity at 30 cm, females at 40 cm. The larval period is about 4-5 years, and it takes another 10 years to reach adulthood.

The salamanders are entirely aquatic and nocturnal. They feed on fresh-water crabs, fish, small amphibians, and additionally on aquatic insects and small mammals. Males and females have overlapping home ranges and are more or less sedentary outside the spawning period. During the breeding season, in August-September, both sexes congregate at underwater nest sites, consisting of 100 to 150 cm long burrows into or near the river bank. Nests have a single entrance opening underwater. Favorable nest sites may be used during successive years. Both males and females may occupy more than one nest at the time, with large and heavy males ("den-masters") attempting to monopolize occupancy of the nest sites. Nests are guarded from inside by males, attacking other males who try to enter. Males may also patrol around the nest area, chasing and attacking other males. Females enter the nests more than once and lay their eggs in the cavity, where they are fertilized by the male. At this stage several other males may intrude and try to fertilize the eggs. After spawning, den-masters remain at the nests for more than one month and aggressively guard the eggs until hatching occurs or until late October. Dominance rank of den-masters among males attempting to breed appears to be strong. Dead and heavily injured males have often been found during September.

The males provide parental care, and for a very long period of time. Males actively seek burrows in stream banks that might serve as sites for mating and nesting. Females enter the burrow, occupied by a "den master" male and mating and external fertilization of the eggs takes place. The den master then provides parental care (tail fanning, agitation of eggs, and hygienic filial cannibalism of unfertilized eggs, or dead or dying embryos and larvae and other specialized behaviors). Such behavior occurs over a long time period, up to seven months. The study adds substantial new information concerning egg deposition and parental care in nature, and will be critical for attempts to improve habitat and other recovery attempts for these amazing animals.