Salmo trutta syn. S. fario

Brown Trout (Salmo fario Linnaeus) (Introduced)
Subject: Brown trout
Author New York Fish and Game Commission
Date 1902
Source/Photographer New York (State). Forest, Fish and Game Commission (1902) Seventh Report of the Forest, Fish and Game Commission of the State of New York, 1901, Albany, NY: J. B. Lyon Company, State Printers, p. 332
Source: https://commons.wikimedia.org/wiki/File%3AFMIB_39198_Von_Behr_Trout_or_European_Brown_Trout_%28Salmo_Fario%29.jpeg

The brown trout (Salmo trutta) is a European species of salmonid fish (Salmonidae) that has been widely introduced into suitable environments globally. The native range of brown trouts extends from northern Norway and White Sea tributaries in Russia in the Arctic Ocean to the Atlas Mountains in North Africa. The western limit of Salmo trutta is Iceland in the north Atlantic, while the eastern limit is in Aral Sea tributaries in Afghanistan and Pakistan.

The lacustrine morph of brown trout is most usually potamodromous, migrating from lakes into rivers or streams to spawn. Salmo trutta morpha fario forms stream-resident populations, typically in alpine streams, but sometimes in larger rivers. Anadromous and non-anadromous morphs coexisting in the same river appear genetically identical. What determines whether or not they migrate remains unknown.

Order: Salmoniformes
Family: Salmonidae
Genus: Salmo
Species: Salmo trutta Linnaeus, 1758