The kirikuchi char, ''Salvelinus leucomaenis japonicus'', is a freshwater

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of ...

in the family

Salmonidae Salmonidae is a family of ray-finned fish that constitutes the only currently extant family in the order Salmoniformes . It includes salmon (both Atlantic and Pacific species), trout (both ocean-going and landlocked), chars, freshwater whitefis ...

. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the

Kii Peninsula The is the largest peninsula on the island of Honshū in Japan. It is named after the ancient Kii Province. Overview The area south of the “ Central Tectonic Line” is called , and is home to reef-like coral communities which are among ...

of central

Honshu , historically called , is the largest and most populous island of Japan. It is located south of Hokkaidō across the Tsugaru Strait, north of Shikoku across the Inland Sea, and northeast of Kyūshū across the Kanmon Straits. The island se ...

in Japan. It is the southernmost population of the char genus ''

Salvelinus ''Salvelinus'' is a genus of salmonid fish often called char or charr; some species are called "trout". ''Salvelinus'' is a member of the subfamily Salmoninae within the family Salmonidae. The genus has a northern circumpolar distribution, and ...

'' and is considered a

relict A relict is a surviving remnant of a natural phenomenon. Biology A relict (or relic) is an organism that at an earlier time was abundant in a large area but now occurs at only one or a few small areas. Geology and geomorphology In geology, a r ...

in its region. It is usually considered a subspecies of the whitespotted char '' Salvelinus leucomaenis'' but was listed as a separate species in the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

(1996). Other subspecies of the whitespotted char ''S. leucomaenis'' have, however, been introduced in the area of the kirikuchi char, which has led to extensive hybridization.Sato T; Demise T; Kubota H; Nagoshi M; Watanabe K (2010) Hybridization, Isolation, and Low Genetic Diversity of Kirikuchi Char, the Southernmost Populations of the Genus ''Salvelinus'' Transactions of the American Fisheries Society 39 2010, 1758 - 1774. Kirikuchi char remain in two separate headwater streams of the Totsu River system, and they retain little genetic variation. The Kirikuchi Char is endangered due to human disturbances, including degradation and overharvesting. Additionally, the species continues to become more endangered due to the loss of genetic diversity from hybridization. Up to 60% of the diet of Kirikuchi char is made up of orthopterans driven into the water by nematomorph parasites. The chars' growth rates are highest in autumn, when nematomorphs influence the behaviour of their hosts to drown themselves.

References

Salvelinus Freshwater fish of Japan Endemic fauna of Japan Taxonomy articles created by Polbot {{Salmoniformes-stub