Wrasses are found worldwide in shallow waters and vary greatly in size. They are invertebrate eaters and forage around coral rubble for food, darting in and out of caves. This is a very interesting fish family because of many things: fish in this family often change sex, there are differences between juveniles and adults and males and females.
The cleaner wrasse offers a cleaning service to all fish that visit its “service station,” usually a definite area on the coral reef. It picks off parasites from the visiting fish’s skin, even from inside the mouth and gills of larger specimens.
While very welcoming, this service has important ramifications for members of this genus; Labroides do this in order to get food and are dependent on other fish bringing it to them. Removing cleaner from the reef results in other species of fish ceasing to visit, as they know that its services will no longer be available.
This dependency between species is a vital part of coral reef life and denuding the reef of cleaner fish is to be discouraged. One also has to consider what the cleaner Wrasse might feed on once the parasites have been cleaned from its tankmates.
Some Wrasses burrow into the substrate at night. This doesn’t hurt them at all. Similar to some Parrot fishes there are Wrasses that manufacture a mucus cocoon within which they spend the night. To ensure that you provide suitable “sleeping accomodation” for these species, the substrate should be sandy and some inches deep.
Wrasses are territorial, which means that considerable thought has to be given to their tankmates, but they are quite hardy. Don’t always assume that the sight of a Wrasse “flashing” off the substrate is a sign of skin irritation – they sometimes adopt this tactic to uncover food.
Look carefully how the Wrasses swim – they hardly use their caudal fins ar all; all of the movement is generated with the pectoral fins, which allows the fish to glide through the water.