Atlantic salmon

The Atlantic salmon (Salmo salar) is a species of ray-finned fish in the family Salmonidae. It is the third largest of the Salmonidae, behind Siberian taimen and Pacific Chinook salmon, growing up to 1 m (3.3 ft) in length. Atlantic salmon are found in the northern Atlantic Ocean and in rivers that flow into it. Most populations are anadromous, hatching in streams and rivers but moving out to sea as they grow where they mature, after which the adults seasonally move upstream again to spawn.

When the mature fish re-enter rivers to spawn, they change in colour and appearance. Some populations of this fish only migrate to large lakes, and are "landlocked", spending their entire lives in freshwater. Such populations are found throughout the range of the species. Unlike Pacific species of salmon, S. salar is iteroparous, which means it can survive spawning and return to sea to repeat the process again in another year with 5–10% returning to the sea to spawn again. Such individuals can grow to extremely large sizes, although they are rare. The different life stages of the fish are known by several different names in English; alevin, fry, parr and smolt.