There is a fish on this reef that counterfeits another fish, and it counterfeits the one everything trusts.
The bluestreak cleaner wrasse runs a service station. Fish queue at it, hold still, open their mouths and lift their gill covers, and let the wrasse pick parasites off them. Almost nothing eats a cleaner wrasse, and its black stripe is one of the safest patterns in the ocean.
This blenny copies it: the pale blue body, the stripe, and the wrasse's bobbing dance that invites a client to pose. A fish comes in, sets itself, and instead of being cleaned has a piece taken out of a fin. The copy is careful enough that where the local cleaner wrasse population wears a different color form, the local false cleanerfish matches that form as well.
It works mostly on the young. Adults that have been bitten learn the difference and drive it off, which is why you occasionally see a large fish charging a small striped one that appears to have done nothing at all.
The tell is the mouth. The wrasse's is at the tip of the snout. This one's opens underneath, because it is built to bite rather than to pick.
The genus. Aspidontus Cuvier 1834 - aspis (viper) + odon (tooth). ETYFish
The species. Aspidontus taeniatus Quoy & Gaimard 1834 - banded. ETYFish
- black stripe on a pale blue body, the same as the cleaner wrasse
- mouth underslung, opening below the snout; the wrasse's opens at the tip
- swims by undulating the whole body, where the wrasse rows with its pectoral fins
- usually near a cleaning station worked by the real thing
- up to 11.5 cm
Why it's threatened
There are no known major threats.
Threat classification from the IUCN Red List.
