Salmon trout is the market name for a large sea trout with pink flesh resembling that of salmon. Sea trout are brown trout that migrate to the sea, where a diet rich in crustaceans colours their flesh pink, just as it does in salmon. The name is commercial rather than scientific, used to signal quality and to distinguish these fine fish from smaller river trout. The flesh is rich, delicate, and excellent poached, baked, or cured, though true salmon is usually fattier. Like all migratory fish it needs clean rivers to spawn, so its presence signals a healthy waterway. Shoppers should note that the name describes appearance and lifestyle, not a separate species.