Bluestreak Cleaner Wrasse

The bluestreak cleaner wrasse is a small member of the wrasse family that runs the "cleaning stations" on reefs. Its body, which shifts from white to blue from front to back, has a black stripe that widens from the snout towards the tail. In the wild large fish come to its station and open their mouths and gills; the cleaner fish eats skin parasites, dead tissue and mucus.

Ethical warning: This species is an obligate cleaner that lives almost entirely on the parasites of other fish. It cannot find this food in a home aquarium; specimens that do not accept prepared food waste away and die within a few weeks to a few months. All specimens are wild-collected, and every fish collected means a cleaning station on the reef left empty. For this reason buying one is not recommended. If cleaning behavior is wanted in the aquarium, cleaner shrimp (Lysmata amboinensis) or captive-bred neon gobies (Elacatinus) are far more sustainable options.

On Indo-Pacific reefs it sets up a cleaning station on a particular rock or coral outcrop; it usually lives as a pair or in a small group made up of one male and several females.

• Volume: At least 200 liters and a mature aquarium housing many fish; in an aquarium with few fish it cannot find food.
• Water: Salinity specific gravity 1.023–1.026, pH 8.1–8.4, temperature 24–27°C.
• Reef compatibility: Reef-safe; it leaves corals and invertebrates alone.

Carnivorous. In the wild it eats parasites. In the aquarium some specimens accept frozen mysis, brine shrimp, fish roe and very fine granules over time; it is essential to see this in the store before buying. It should be fed small amounts several times a day.

Peaceful; it constantly approaches other fish and tries to clean them. Some fish are bothered by this persistence.

Good companions: Peaceful, medium-sized reef fish: tangs, dwarf angelfish, anthias, clownfish.

Avoid: Lionfish and predators that can fit it in their mouths; small aquariums with few fish.

A single specimen is kept in the aquarium. A pair can find enough food only in very large, well-stocked aquariums.

In the wild it forms harems made up of one male and several females; if the male dies, the dominant female changes into a male. A pelagic spawner. Breeding it in the aquarium is not common; captive-bred specimens are almost unavailable.

• Starvation: This is the biggest problem; the belly caves in and the color fades.
• Confusion with the mimic blenny: The false cleanerfish (Aspidontus taeniatus) mimics this species and tears pieces from fishes' skin; the position of its mouth differs (in the blenny it is underneath).
• Marine white spot and velvet: Like other fish, quarantine is needed.

Cannot be distinguished externally; males are usually the largest individual in the group.