Cleaner Wrasse

The Cleaner Wrasse (Labroides dimidiatus) is a small wrasse in the family Labridae, renowned for its cleaning symbiosis with a wide range of larger reef fish. Found throughout the tropical Indo-Pacific from the Red Sea and East Africa to the central Pacific, it establishes fixed cleaning stations on the reef where client fish visit to have parasites and dead tissue removed. This behavior is one of the best-studied examples of interspecies cooperation in marine ecosystems. The species is abundant and not considered at risk, and its cleaning role makes it an ecologically important species that several reef fish, including some blennies, mimic for protective advantage.

The Cleaner Wrasse is identified by:

• Slender, elongate body reaching 8-11 cm
• Pale blue to white body crossed by a single broad black horizontal stripe from the snout through the tail, widening toward the rear
• Small, slightly upturned mouth
• Forked tail fin
• A distinctive undulating, almost hovering swimming style used while working at cleaning stations

It closely resembles the mimic blenny (Aspidontus taeniatus), which imitates the Cleaner Wrasse's coloration and swimming pattern to approach unsuspecting fish, but the blenny has a more elongated body and an underslung mouth adapted for biting rather than the wrasse's small terminal mouth.

Cleaner Wrasse are found throughout the tropical Indo-Pacific, from the Red Sea and East Africa to the central Pacific islands and southern Japan. They inhabit coral reefs and rocky reef habitat at depths of 1 to 40 meters, establishing fixed cleaning stations at prominent reef locations such as coral heads or rock outcrops that client fish can easily locate and revisit. They favor clear tropical water generally between 24-29°C and are closely tied to reef structure that supports a steady stream of visiting client fish. Juveniles and adults both maintain cleaning stations, sometimes independently.

Cleaner Wrasse operate individually or in small groups at established cleaning stations, where client fish, including many larger predatory species, pause to have ectoparasites, dead skin, and mucus removed from their body, gills, and mouth. This mutualistic relationship benefits both parties, reducing parasite loads on client fish while providing a reliable food source for the wrasse. They use a distinctive hovering, undulating swim to signal their cleaning service to approaching fish. Cleaner Wrasse are protogynous hermaphrodites living in small harem groups with a dominant male, and can change sex from female to male when needed. Pair spawning occurs near dusk with pelagic eggs released into the water column.