Salmon

Salmon (; pl.: salmon) are any of several commercially importantspecies of euryhalineray-finned fish from the generaSalmo and Oncorhynchus of the familySalmonidae, native to tributaries of the North Atlantic (Salmo) and North Pacific (Oncorhynchus) basins. Salmon is a colloquial or common name used for fish in this group, but is not a scientific name. Other closely related fish in the same family include trout, char, grayling, whitefish, lenok and taimen, all coldwater fish of the subarctic and cooler temperate regions with some sporadic endorheic populations in Central Asia.

Salmon are typically anadromous: they hatch in the shallow gravelbeds of freshwaterheadstreams and spend their juvenile years in rivers, lakes and freshwater wetlands, migrate to the ocean as adults and live like sea fish, then return to their freshwater birthplace to reproduce. However, populations of several species are restricted to fresh waters (i.e. landlocked) throughout their lives. Folklore has it that the fish return to the exact stream where they themselves hatched to spawn, and tracking studies have shown this to be mostly true. A portion of a returning salmon run may stray and spawn in different freshwater systems; the percent of straying depends on the species of salmon. Homing behavior has been shown to depend on olfactory memory.

Salmon are important food fish and are intensively farmed in many parts of the world, with Norway being the world's largest producer of farmed salmon, followed by Chile. They are also highly prized game fish for recreational fishing, by both freshwater and saltwater anglers. Many species of salmon have since been introduced and naturalized into non-native environments such as the Great Lakes of North America, Patagonia in South America and South Island of New Zealand.