(Zool.) Any one of numerous species of fishes belonging to Salmo, Salvelinus, and allied genera of the family Salmonidae. 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. 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.