The Atlantic salmon (Salmo salar) is a species of ray-finned fish in the family Salmonidae. It is found in the northern Atlantic Ocean, in rivers that flow into the north Atlantic and, due to human introduction, in the north Pacific Ocean. Atlantic salmon have long been the target of recreational and commercial fishing, and this, as well as habitat destruction, has reduced their numbers significantly; the species is the subject of conservation efforts in several countries.
The Atlantic salmon was given its scientific binomial name by zoologist and taxonomist Carl Linnaeus in 1758. The name, Salmo salar, derives from the Latin salmo, meaning salmon, and salar, meaning leaper, according to M. Barton, but more likely meaning "resident of salt water". Lewis and Short's Latin Dictionary (Clarendon Press, Oxford, 1879) translates salar as a kind of trout from its use in the Idylls of the poet Ausonius (4th century CE). Later, the differently coloured smolts were found to be the same species.
Other names used to reference Atlantic salmon are: bay salmon, black salmon, caplin-scull salmon, Sebago salmon, silver salmon, fiddler, or outside salmon. At different points in their maturation and life cycle, they are known as parr, smolt, grilse, grilt, kelt, slink, and spring salmon. Atlantic salmon that do not journey to sea are known as landlocked salmon or ouananiche.