The Kamchatkan rainbow trout (''Oncorhynchus mykiss mykiss'') is a

subspecies In Taxonomy (biology), biological classification, subspecies (: subspecies) is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (Morphology (biology), morpholog ...

of the

rainbow trout The rainbow trout (''Oncorhynchus mykiss'') is a species of trout native to cold-water tributary, tributaries of the Pacific Ocean in North America and Asia. The steelhead (sometimes called steelhead trout) is an Fish migration#Classification, ...

, which is a

fish A fish (: fish or fishes) is an aquatic animal, aquatic, Anamniotes, anamniotic, gill-bearing vertebrate animal with swimming fish fin, fins and craniate, a hard skull, but lacking limb (anatomy), limbs with digit (anatomy), digits. Fish can ...

in the family

Salmonidae Salmonidae (, ) is a family (biology), family of ray-finned fish, the only extant member of the suborder Salmonoidei, consisting of 11 extant genera and over 200 species collectively known as "salmonids" or "salmonoids". The family includes salmo ...

. It is native to

Russian Far East The Russian Far East ( rus, Дальний Восток России, p=ˈdalʲnʲɪj vɐˈstok rɐˈsʲiɪ) is a region in North Asia. It is the easternmost part of Russia and the Asia, Asian continent, and is coextensive with the Far Easte ...

. Its main range is on the

Kamchatka Peninsula The Kamchatka Peninsula (, ) is a peninsula in the Russian Far East, with an area of about . The Pacific Ocean and the Sea of Okhotsk make up the peninsula's eastern and western coastlines, respectively. Immediately offshore along the Pacific ...

, and it has also been recorded from the

Commander Islands The Commander Islands, Komandorski Islands, or Komandorskie Islands (, ''Komandorskiye ostrova'') are a series of islands in the Russian Far East, a part of the Aleutian Islands, located about east of the Kamchatka Peninsula in the Bering Sea. ...

east of Kamchatka, and sporadically in the

Sea of Okhotsk The Sea of Okhotsk; Historically also known as , or as ; ) is a marginal sea of the western Pacific Ocean. It is located between Russia's Kamchatka Peninsula on the east, the Kuril Islands on the southeast, Japan's island of Hokkaido on the sou ...

, as far south as the mouth of the

Amur River The Amur River () or Heilong River ( zh, s=黑龙江) is a perennial river in Northeast Asia, forming the natural border between the Russian Far East and Northeast China (historically the Outer and Inner Manchuria). The Amur ''proper'' is ...

Size

This species reaches a length of .

Sea-run and freshwater ecotypes

The Kamchatkan rainbow trout ("mikizha") comprises various ecological forms, including

anadromous Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousa ...

and resident freshwater forms and their intermediates. Russian taxonomy has long attributed the rainbow trout to the genus ''Parasalmo'', and has further considered the Kamchatkan rainbow trout as composed of two distinct species, ''Parasalmo mykiss'' and ''Parasalmo penshinensis'', whose ranges overlap. ''P. mykiss'' is a resident freshwater and estuary form, whereas ''P. penshinensis'', "Kamchatkan salmon", is the sea-run, migrating

form, which may grow to a length of 100 cm and 11–12 kg weight (as with the American

steelhead Steelhead, or occasionally steelhead trout, is the Fish migration#Classification, anadromous form of the coastal rainbow trout or Columbia River redband trout (''O. m. gairdneri'', also called redband steelhead). Steelhead are native to cold-wa ...

). ''P. penshinensis'' is considered

critically endangered An IUCN Red List critically endangered (CR or sometimes CE) species is one that has been categorized by the International Union for Conservation of Nature as facing an extremely high risk of extinction in the wild. As of December 2023, of t ...

(CR) in the Red Book of Kamchatka.Красная книга Камчатки. Том 1. Животные
(Red Book of Kamchatka) Modern research however suggests that the two forms represent the same species, showing no genetic isolation or differences.
www.nexplorer.ru:news
Позвоночные животные России sevin.ru

References

Oncorhynchus Fish described in 1792 Taxa named by Johann Julius Walbaum {{Salmoniformes-stub