False Cleanerfish

The false cleanerfish primarily lives in coral reef margins among the cleaning stations of the bluestreak cleaner wrasse (Labroides dimidiatus), and are usually seen near locations of one or more L. 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, some individuals have been witnessed to mimic the appearance of other reef fish, as well as atypically colored cleaner wrasses that live in the same territory. 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. It is not known whether the false cleanerfish adopts a permanent color pattern or if it alters its coloration to mimic the appearance of neighboring cleaner wrasses. One major difference in appearance between the false cleanerfish and its model is the location of the mouth. A. taeniatus has an underslung mouth, whereas L. dimidiatus has its mouth in the terminal position. …

The false cleanerfish has been observed to mimic the unusual "dance" of the bluestreak cleaner wrasse by spreading its caudal fin and oscillating its posterior end up and down. By doing so, the false cleanerfish elicits the same posing behavior in client fish, similarly to L. dimidiatus. Occasionally, however, rather than feeding on ectoparasites like the cleaner wrasse, the false cleanerfish will attack and attempt (and sometimes succeed) at tearing away portions of fin from the client fish. This typically occurs and is most successful with juvenile client fish, as adults have been evidenced to avoid or even indiscriminately attack cleanerfish, suggesting adult client fish remember being attacked. Also, evidence indicates adult fish are able to distinguish between L. dimidiatus and A. taeniatus, and thus avoid it altogether.