The Cleaner Wrasse (Labroides dimidiatus) also known as the Blue Streak Cleaner Wrasse is a common feature on reefs along the East African coast. They are found singly or more commonly in pairs and on some occasions larger groupings may be seen but a pair is the norm.
The fish have a black stripe down the center of the body through the eye and tend to be light blue above and below the stripe. There are minor color variations and sometimes a small patch of white may be seen towards the tail and on some fish the front section is more silver than blue. Proportionally they have a long thin body with a pointy nose and a wide flat tail. On Kankadya reef off Dar es Salaam there is an area where all the specimens are a bright yellow above the black line which is an unusual variation. The fish is a protogynous hermaphrodite and changes sex over its lifetime.
IN THE WILD
The individuals and pairs will set up in a specific location in what are known as cleaning stations and will bob their rear up and down in a very distinctive motion . They have what is known as a mutualistic relationship with other reef dwellers and sometimes pelagic fish will also visit the cleaning stations. The dance of the Cleaner Wrasse seems to have an effect on the fishes that come to the station and the fishes in the area remain quiet and they will sit still in one position while the Cleaner Wrasse goes into their gills and sometimes open mouths nipping off small parasites and dead skin or slime from the visitor.
In many years of diving I have never seen a predatory action by any fish around a proper feeding station (excluding those of the mimics) and the area seems almost a zone of neutrality, a place where peace exists among the different visitors. If a diver approaches, the resident Cleaner will often drop his task and swim in front of the diver bobbing his tail rapidly up and down in what is clearly a behavior understood by the other fishes. It almost seems as though they are trying to tell you “this a cleaning station, no eating other fishes allowed here. ”
The Blue Streak Cleaner is found across the Indian Ocean from the East Cost of Africa all the way to Polynesia. They grow up to 15 centimeters in length.
Because they are so tame Cleaner Wrasses are easy to catch with a net, although many novice aquarists have learnt the hard way that there are Blennies that mimic them. The Bluestreak Fangblenny (Plagiotremus rhinorhynchos) is a pretty good mimic of a juvenile Cleaner Wrasse when it bites chunks out of the flesh of the fishes in their tank it can be very difficult to catch once in a tank.
To keep a Cleaner Wrasse happy in a tank one needs quite a large number of fish in the tank, otherwise it may enthusiastically chase the fish and may stress certain types of fish. Two may be kept in a tank but care should be taken that they are indeed a pair and not two males. Sensibly a single small juvenile is a good choice as its feeding requirements are lower and they are easier to move onto a shrimp/meat diet.
BLUESTREAK CLEANER WRASSE CLASSIFICATION