The false cleanerfish (Aspidontus taeniatus) is a species of combtooth blenny, a mimic that copies both the dance and appearance of Labroides dimidiatus (the bluestreak cleaner wrasse), a similarly colored species of cleaner wrasse. It likely mimics that species to avoid predation, as well as to occasionally bite the fins of its victims rather than consume parasites. Most veiled attacks occur on juvenile fish, as adults that have been attacked in the past may avoid or even attack A. taeniatus.
It is indigenous to coral reef habitats in the Indo-Pacific.
Mimicry
Appearance
The false cleanerfish primarily lives in coral reef margins among the cleaning stations of the bluestreak cleaner wrasse (Labroides dimidiatus), With its territory primarily overlapping with its model fish, the false cleanerfish mimics both the appearance and occasionally the behavior of said fish. Though A. taeniatus is typically known to exhibit the characteristic black stripe and blue body and general body shape and structure of L. dimidiatus,
Juvenile A. taeniatus fish match the appearance of juvenile L. dimidiatus (black body, blue dorsal stripe), and continue to match the coloration of cleaner wrasses of the same size throughout growth. This typically occurs and is most successful with juvenile client fish, Also, evidence indicates adult fish are able to distinguish between L. dimidiatus and A. taeniatus, and thus avoid it altogether.—the primary stomach contents of L. dimidiatus. Additionally, close observation of A. taeniatus has shown them to only attack posing clients at a rate of about 20%. Furthermore, false cleanerfish inflict a higher cost on their models and cleaning stations when cheating, as client fish are more likely to behave aggressively or avoid cleaning stations altogether if they are consistently attacked.
However, there is evidence of geographical variation on the benefits obtained by the mimicry: whereas in the Red Sea and the Great Barrier Reef foraging on tube worms or substrate was more common than attacks by mimics, in French Polynesia and Indonesia false cleanerfish (especially juveniles) fed on client fish tissue more commonly than other food sources. Furthermore, the behavior of A. taeniatus mimicking L. dimidiatus in a largely nonaggressive way supports the hypothesis of the evolution of reciprocally altruistic behavior.