Copies the cleaner wrasse closely enough to be allowed in, then takes a bite of fin instead of a parasite. The mouth is underslung.
To about 12 cm, slender, with a dark stripe running the length of the body over a pale blue ground — a close copy of the cleaner wrasse it lives alongside. The difference is the mouth. A cleaner wrasse’s mouth is terminal, at the tip of the snout; this blenny’s is underslung, set back beneath the head, because it is built to take a bite rather than to pick.
That is what it does. It copies the cleaner closely enough to be allowed in by fish waiting at a station, and then takes a piece of fin or skin instead of a parasite. It is a textbook case of aggressive mimicry and it is watchable: sit back from a cleaning station and the fish that gets a sudden reaction from its client is this one rather than the wrasse. It is a Red Sea species.
Ratings are per location: 1 means found on most dives that look for it, 5 means a handful of records. Where enough dives have been logged the figure is calculated from them; otherwise it is an editorial estimate, and says so. We publish habitat and destination, not the dive site.