This species reaches a length of 122 cm (48 in).[5]
Sea-run and freshwater ecotypes
The Kamchatkan rainbow trout ("mikizha") comprises various ecological forms, including anadromous and resident freshwater forms and their intermediates.[6][7] 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 anadromous form, which may grow to a length of 100 cm and 11–12 kg weight (as with the American steelhead).[8]P. penshinensis is considered critically endangered (CR) in the Red Book of Kamchatka.[8][6] Modern research however suggests that the two forms represent the same species, showing no genetic isolation or differences.[6][9]
^David Starr Jordan; Barton Warren Evermann; Howard Walton Clark (1930). Report of the United States Commissioner of Fisheries for the fiscal year 1928-Checklist of the fishes and fishlike vertebrates of North America north of the northern boundary of Venezuela and Colombia. Washington, D.C.: United States Department of Interior, Fish and Wildlife Service.
