Fishby LogoFishby

Rainbow Smelt and Similar Species

Osmerus mordax

Got a photo? Identify fish instantly with the Fishby app.

Open the app

Several fish can be confused with Rainbow Smelt. Here are the key differences.

Species often confused with {name}

European Smelt

Osmerus eperlanus

Key differences: Very similar in appearance and often confused. O. eperlanus generally has a slightly shorter maxilla (upper jaw) that does not extend as far back as the posterior margin of the eye, and typically fewer gill rakers (28-35 vs. 32-40 in O. mordax). Genetic analysis is often required for definitive differentiation in areas of overlap.

Longfin Smelt

Spirinchus thaleichthys

Key differences: Distinguished by its much longer pectoral fins, which extend beyond the origin of the dorsal fin. Also typically has a more compressed body and a smaller mouth.

Eulachon (Candlefish)

Thaleichthys pacificus

Key differences: Generally larger, with a more robust body and a distinctive oily texture. The mouth is smaller, and the teeth are less prominent. Eulachon also have concentric striations on the operculum (gill cover) which are absent in Rainbow Smelt.

Explore Rainbow Smelt

Identify fish anywhere

Free on iOS, Android, and Web. Photo identification, full species details, and more.

Open in app