Salmo fario

Trout Trout (trout), n. [AS. truht, L. tructa, tructus; akin to Gr. trw`kths a sea fish with sharp teeth, fr. trw`gein to gnaw.] 1. (Zo["o]l.) Any one of numerous species of fishes belonging to {Salmo}, {Salvelinus}, and allied genera of the family {Salmonid[ae]}. They are highly esteemed as game fishes and for the quality of their flesh. All the species breed in fresh water, but after spawning many of them descend to the sea if they have an opportunity. [1913 Webster]

Note: The most important European species are the river, or brown, trout ({Salmo fario}), the salmon trout, and the sewen. The most important American species are the brook, speckled, or red-spotted, trout ({Salvelinus fontinalis}) of the Northern United States and Canada; the red-spotted trout, or Dolly Varden (see {Malma}); the lake trout (see {Namaycush}); the black-spotted, mountain, or silver, trout ({Salmo purpuratus}); the golden, or rainbow, trout (see under {Rainbow}); the blueback trout (see {Oquassa}); and the salmon trout (see under {Salmon}.) The European trout has been introduced into America. [1913 Webster]

2. (Zo["o]l.) Any one of several species of marine fishes more or less resembling a trout in appearance or habits, but not belonging to the same family, especially the California rock trouts, the common squeteague, and the southern, or spotted, squeteague; -- called also {salt-water trout}, {sea trout}, {shad trout}, and {gray trout}. See {Squeteague}, and {Rock trout} under {Rock}. [1913 Webster]

{Trout perch} (Zo["o]l.), a small fresh-water American fish ({Percopsis guttatus}), allied to the trout, but resembling a perch in its scales and mouth. [1913 Webster]