Von Behr Trout Salmo trutta syn. S. fario
Salmo fario Will. Von Behr Trout. One-half natural size
Subject: Salmo, Brown trout, Trypanosoma
Author Barton Warren Evermann (1853–1932)
Date 1891
Source/Photographer Evermann, Barton W. (1893) Reconnaissance of the streams and lakes of western Montana and northwestern Wyoming, Bulletin of the United States Fish Commission, vol. 11, 1891, Washington, DC: Government Printing Office
Source: https://commons.wikimedia.org/wiki/File:FMIB_34334_Salmo_fario_will_Von_Behr_Trout.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.

Salmo trutta fario, sometimes called the river trout, and also known by the name of its parent species, the brown trout, is a predatory fish of the family Salmonidae and a subspecies or morph of the brown trout species, Salmo trutta, which also includes sea trout (Salmo trutta trutta) and a lacustrine trout (Salmo trutta lacustris).

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