Scientific classification: Salmon belong to the family Salmonidae.
Salmon (fish), common name applied to fish characterized by an elongate body covered with small cycloid (rounded, with smooth edges) scales and possessing an adipose (fleshy) fin between the dorsal fin and tail. These fish belong to the salmon family. Most members of this family are valuable food fish and excellent game fish. They are found in both fresh and salt water in the colder regions of the northern hemisphere. Many return from salt water to fresh water to breed, and the young migrate to salt water from fresh water after they reach maturity. The migratory instinct of members of the salmon family is remarkably specific, each generation returning to spawn in exactly the same breeding places as the generation before it. Even those species that do not migrate from fresh water to salt water spawn in the same freshwater streams as did their ancestors. The spawning ground of these fish is usually a rapidly flowing, clear stream with gravel and rocks on the bottom.