Salmon family includes trout, whitefish, chars and graylings - together they form a family of ray-finned fish. Found throughout the northern hemisphere, the family includes species important to commercial and sport interests, which has resulted in their introduction to other waters of the world. Almost all species are anadromous: they live in the open ocean and swim up river to spawn in clean and cold freshwater. These are mostly large, predatory fish that reach lengths of up to two metres and prey on crustaceans, insects and smaller fish.