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). Depending on the supply of food, river trout measure 20 to 80 cm (0.7–2.6 ft) in length; exceptionally they may be up to 1 m (3.3 ft) long and weigh up to over 13 kg (29 lb). Their back is olive-dark brown and silvery blue, red spots with light edges occur towards the belly, the belly itself is whitish yellow. River trout usually attain a weight of up to 2 kg (4.4 lb). They can live for up to 18 years.