Six-line wrasse

The six-line wrasse (Pseudocheilinus hexataenia) is a small marine fish in the wrasse family, found across a broad Indo-Pacific range and closely tied to coral reefs. It reaches a maximum length of about 10 centimeters. Its body is violet, marked with six orange stripes along the sides, and it has a small eyespot on the upper part of the tail fin base, a blue stripe along the anal fin base, a blue streak on the pelvic fins, and red eyes. First described in 1857 by Dutch ichthyologist Pieter Bleeker as Cheilinus hexataenia, with the type locality of Ambon in the Moluccas, it later became the type species for the genus Pseudocheilinus when Bleeker established that genus in 1862.

This species ranges from the eastern coast of Africa—from the Red Sea down to South Africa—across the Indian Ocean and into the western Pacific, north to Japan, south to northern Australia, and east to Tuamotu. It lives among coral branches on seaward reefs, in clear coastal waters, and on reef crests or slopes in shallow water, recorded to depths of about 20 meters. Shy and secretive, it typically moves in small, loose groups among coral branches for protection.

Its diet consists mainly of small crustaceans, and it has been observed acting as a cleaner fish, removing ectoparasites like copepods and isopods from other fish. In Japan’s Izu Islands, spawning occurs just before sunset, with paired adults making a quick dash to the surface to release eggs, reducing predation risk.

Diurnal, it sleeps at night inside cavities within a mucus cocoon, thought to mask its scent from nocturnal predators. The six-line wrasse is popular in the aquarium trade, though it has not been bred in captivity. In parts of Thailand, Sea Gypsies collect it for food.