Bicolor Blenny Identification Guide
Identify the Bicolor Blenny by its sharply split coloration, dark brown front half and bright orange rear half.
Read the full Bicolor Blenny encyclopedia entry →
Key identification features
- Elongated, blenny-shaped body with a blunt head and single long dorsal fin running its length
- Front half of the body dark brown to nearly black
- Back half, including the tail, bright orange to yellow-orange, creating a clear two-tone split
- Small tentacle-like cirri may be present above the eyes in some individuals
- Usually under 4 inches, with a slightly humped forehead in mature males
- Often seen resting on rubble or perched at the entrance to a burrow rather than swimming in open water
Common look-alikes
- Two-tone (Redlip) blenny: shows a similar two-tone split but adds a bright red-orange lip line that Bicolor Blennies lack.
- Canary blenny: solid bright yellow overall with no dark front-half coloration.
- Midas blenny: solid orange-yellow body without any dark anterior half, and a more elongated, fish-like swimming posture.
Where you'll see one
Bicolor Blennies live on Indo-Pacific reef flats and lagoons, usually in shallow water under 20 meters where rubble, dead coral, or old worm tubes provide burrow sites. They spend most of their time perched near a bolt-hole, darting out to feed on algae and small invertebrates before retreating quickly at the first sign of disturbance, so patient, close observation near rubble patches is often needed to spot one.
Frequently asked questions
How do I tell a Bicolor Blenny from a Two-tone Blenny?
Look at the lips: Two-tone Blennies show a distinct reddish lip line at the color break, while Bicolor Blennies have a clean dark-to-orange split with no red lip marking.
What behavior confirms it's a blenny and not a similar small goby?
Bicolor Blennies rest propped on their pelvic fins near a burrow and dart in short bursts along the substrate, whereas superficially similar gobies tend to hover just above the bottom rather than perch directly on it.
Bicolor Blenny identified by the community
Recent Bicolor Blenny catches identified with Fish Identifier.
