Ryan Hagerty / USFWS · Public domain
Species guide
Rainbow Trout
Oncorhynchus mykiss
A variable salmonid whose spots, adipose fin and side band must be read alongside life history and local stocking records.
Habitat
Cold, well-oxygenated streams and lakes; some populations migrate through estuaries and the ocean.
Habitat supports a shortlist; it does not prove an identity. Water bodies change seasonally, and introduced populations may occur outside the best-known native setting.
Range
Native to Pacific drainages of North America and northeastern Asia; introduced widely around the world.
Check a current state, provincial or national fisheries record before making a high-confidence range claim. Drainage boundaries are more informative than political borders.
Compare carefully
Steelhead are the sea-going life-history form of the same species; a photograph alone cannot always establish life history.
When a decisive structure is hidden, record the observation as probable or unresolved. An honest uncertainty is more useful than a precise label built from incomplete evidence.
Responsible observation
Prioritize an in-water image showing the tail spots, adipose fin and full side. Local regulations may protect specific populations.
For a live fish, prepare the camera first, use wet hands when handling is unavoidable, support the body and return it promptly according to local rules.