The false cleanerfish (''Aspidontus taeniatus'') is a species of
combtooth blenny, a
mimic
MIMIC, known in capitalized form only, is a former simulation computer language developed 1964 by H. E. Petersen, F. J. Sansom and L. M. Warshawsky of Systems Engineering Group within the Air Force Materiel Command at the Wright-Patterson AFB in ...
that copies both the dance and appearance of ''
Labroides dimidiatus
The bluestreak cleaner wrasse, ''Labroides dimidiatus'', is one of several species of cleaner wrasses found on coral reefs from Eastern Africa and the Red Sea to French Polynesia. Like other cleaner wrasses, it eats parasites and dead tissue off ...
'' (the bluestreak cleaner wrasse), a similarly colored species of
cleaner wrasse
The wrasses are a family, Labridae, of marine fish, many of which are brightly colored. The family is large and diverse, with over 600 species in 81 genera, which are divided into 9 subgroups or tribes.
They are typically small, most of them le ...
. It likely mimics that species to avoid predation,
as well 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
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Co ...
habitats in the
Indo-Pacific
The Indo-Pacific is a vast biogeographic region of Earth.
In a narrow sense, sometimes known as the Indo-West Pacific or Indo-Pacific Asia, it comprises the tropical waters of the Indian Ocean, the western and central Pacific Ocean, and the ...
.
Mimicry
Appearance
The false cleanerfish primarily lives in
coral reef
A coral reef is an underwater ecosystem characterized by reef-building corals. Reefs are formed of colonies of coral polyps held together by calcium carbonate. Most coral reefs are built from stony corals, whose polyps cluster in groups.
Co ...
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.
Additionally, the false cleanerfish has a small set of teeth on the upper mandible, as well as enormous canines that protrude from its lower jaw and fit into sockets laterally on the roof of its mouth.
Cheating behaviour
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.
Evolutionary basis
Though ''A. taeniatus'' mimics ''L. dimidiatus'' in color, morphology, and mode of swimming, the false cleanerfish cheats much less often than initially reported.
The stomach contents of ''A. taeniatus'' consist primarily of the
demersal
The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of ...
eggs of fishes and the tentacles of
tube worms
A tubeworm is any worm-like sessility (zoology), sessile invertebrate that anchors its tail to an underwater surface and secretes around its body a mineral tube, into which it can withdraw its entire body.
Tubeworms are found among the following t ...
,
with a relatively small portion of fish fins, or ectoparasites
—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%.
The primary reason for the false cleanerfish's mimicry is suggested to be not to cheat and feed on the flesh of client fish, but to avoid predation by those fish that do not prey on ''L. dimidiatus''.
Aggressive mimicry typically results in the complete consumption of prey by a mimic predator (such as
anglerfish
The anglerfish are fish of the teleost order Lophiiformes (). They are bony fish named for their characteristic mode of predation, in which a modified luminescent fin ray (the esca or illicium) acts as a lure for other fish. The luminescence ...
), or partial consumption of prey by an unattractive mimic.
In both cases, the host fish can rarely or never learn the disguise of the mimic; the fact that ''A. taeniatus'' can be easily identified by client fish helps to dispel the notion that it is primarily an aggressive mimic.
Groupers raised in captivity do not attack ''L. dimidiatus'', while they do consume all other noncleanerfish on sight.
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
The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; T ...
and the
Great Barrier Reef
The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...
foraging on tube worms or substrate was more common than attacks by mimics, in
French Polynesia
)Territorial motto: ( en, "Great Tahiti of the Golden Haze")
, anthem =
, song_type = Regional anthem
, song = " Ia Ora 'O Tahiti Nui"
, image_map = French Polynesia on the globe (French Polynesia centered).svg
, map_alt = Location of Frenc ...
and
Indonesia
Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...
false cleanerfish (especially juveniles) fed on client fish tissue more commonly than other food sources.
An alternate reason for the mimicry behavior of ''A. taeniatus'' is to deceive
egg-caring fishes so to more easily gain access to their eggs; however, little evidence favors this possibility.
The evolution of ''A. taeniatus'' to mimic ''L. dimidiatus'' has been used as evidence for the strong selection of client fish that do not attack their cleaners, or cheat and consume their cleaners after cleaning.
Furthermore, the behavior of ''A. taeniatus'' mimicking ''L. dimidiatus'' in a largely nonaggressive way supports the hypothesis of the evolution of reciprocally altruistic behavior.
References
External links
''Aspidontus taeniatus'', False cleanerfisha
FishBase''Aspidontus taeniatus''a
ITIS*
{{Taxonbar, from=Q1413670
False cleaner fish
Fish described in 1834