Family : Blenniidae
Text © Giuseppe Mazza
English translation by Mario Beltramini
The False cleanerfish (Aspidontus taeniatus) differs from Labroides dimidiatus for the mouth that is not placed at end of the body but under the snout © Nigel Marsh
The False cleanerfish (Aspidontus taeniatus Quoy & Gaimard, 1834), belongs to the class of the
Actinopterygii, the ray-finned fish, to the order of the Blenniiformes and to the family of the Blenniidae, that. counts 59 genera and more than 400 species, mostly marine, but present also in the fresh waters and in the brackish ones of the estuaries.
They are fish without scales, known as combtooth blennies, due to their jaws equipped with tiny teeth arranged in parallel like a comb, for seizing and grinding the small benthic invertebrates they feed on.
The False cleanerfish however additionally has, on the lower jaw, also two showy sabre-toothed teeth, invisible when the mouth is closed being hidden in a dedicated housing between the bones of the skull, but that can suddenly appear, opening it, like the folding teeth of the vipers. A characteristic present in the etymology of the genus Aspidontus, created by Cuvier in 1634 and in Greek composed by “aspis”, viper, and “odon”, tooth.
Then opening it shows two huge canines like those of the viperids, hence the genus Aspidontus from the Greek “aspis”, viper and “odon” tooth © Anna & Ned DeLoach
Conversely, the specific term taeniatus originates from the Latin “taenia”, ribbon, band, and therefore it is matter of a fish “with the band”, referring to the conspicuous dark lateral band of the adults.
Zoogeography
Aspidontus taeniatus has a very vast distribution range in the eastern Indo-Pacific. Starting from the Red Sea and from South Africa, we, as a matter of fact, find it in Australia and in Japan, and then up to French Polynesia, Marquesas Islands and Tuamotu.
Ecology-Habitat
Aspidontus taeniatus lives associated with the coral reef between 1 and 25 m of depth.
Like other Blenniiformes lives in the tubes abandoned by annelids, but also in similarly long cavities and even in the glass bottles it finds at times on the seabed © Glen Whisson
It live in tubes abandoned by the annelids and similar cavities, up to the empty glass bottles ended up at the bottom of the sea, not far from the “cleaning stations”, outpatient clinics often managed by Labroides dimidiatus, a cleaning wrasse who frees fish from parasites of the skin and of the gills without neglecting the food leftovers between the teeth.
Among its customers stand also big predators like the groupers, and then, to avoid being taken for a bite, the cleaning wrasse appears with a particular dancing swim, an up and down of the extended caudal fin, that, associated with the characteristic livery are a clear certificate of membership to the medical corps.
Aspidontus taeniatus, cunningly, imitates its dance and livery, but once caught up the patient, after removing some parasites, not happy with the food scraps, unleashes its sabre-toothed teeth snatching without scruples shreds of flesh and fins.
Often lives in small schools in the tropical Indo-Pacific, not far from the cleaning stations where Labroides dimidiatus, honest cleaner, frees fish from the skin parasites © Dawn Goebbels
Morphophysiology
The False cleanerfish reaches at maximum a length of 11,5 cm, with a body little compressed on the sides.
The head is pointed and the mouth, bigger than that of Labroides dimidiatus, is not located like the latter at the extremity of the body, but under the snout.
The dorsal fin has 10-12 spines and 26-28 soft rays that touch rounding the caudal fin. The anal, with 2 spiny rays and 25-28 unarmed, is specular to the other. The pelvic ones have one spiny ray and 3 unarmed; the pectoral ones 13-15 rays, and the caudal is truncated, trapezoidally shaped with rounded borders.
To fool the clients of cleaning labrid, Aspidontus taeniatus perfectly imitates the livery and where this displays a showy yellow spot does not hesitate in adopting it. From top © François Libert – © Nico K. Michiels – © Mark Rosenstein
The background livery is clear, beige and turquoise blue, with a dark blue line that starting from the snout conceals the eye and reaches, widening, the tail. Also the dorsal fin and the anal have a similar dark line, thin and emphasized above and below by the bright turquoise.
Exactly the same colours of Labroides dimidiatus, to such a point that in the locations where this one has a showy yellow spot close to the tail, the same can be found also in Aspidontus taeniatus.
Ethology-Reproductive Biology
The False cleanerfish often lives in small schools or in couples living together in the same den.
Gets closer with the true cleaner same dance, wagging like Labroides dimidiatus the spread caudal, but with the canines ready for tearing off shreds of flesh and fins © uwkwaj
Useless to say that the old clients of the cleaning stations learn over time to recognize the impostors and take their revenge. For this reason Aspidontus taeniatus usually offers its services to the newcomers who do not know him.
However, it also feeds on benthic invertebrates, zooplankton, worms and eggs of demersal fish. Rather, accurate research show that in their stomach the fins of the victims and the ectoparasites are significantly inferior.
Aspidontus taeniatus reproduces in pairs gluing the eggs to the seabeds on a pedestal or on an adhesive pad.
The planktonic larvae are then mostly found in shallow waters along the coast.
Juvenile with showy rays typical of the age. Aspidontus taeniatus feeds also on crustaceans, zooplankton, worms and eggs of demersal fish. It is not an endangered species © Ashley Parr
The resilience of the species is excellent, with a possible doubling of the populations in less than 15 months, and the fishing vulnerability is very low, marking only 10 on a scale of 100.
Consequently, since 2000 Aspidontus taeniatus appears as “LC, Least Concern”, in the IUCN Red List of the endangered species.
Synonyms
Aspidontus taeniatus taeniatus, Quoy & Gaimard, 1834; Blennechis filamentosus Valenciennes, 1836; Aspidontus filamentosus (Valenciennes, 1836); Aspidontus tractus Fowler, 1903; Aspidontus taeniatus tractus Fowler, 1903.
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