Labrichthys

Lore & Background

The tubelip wrasse was formally described in 1847 as Cossyphus unilineatus by French naturalist Alphonse Guichenot, with the type locality given as Guam. In 1854, Dutch ichthyologist Pieter Bleeker placed it in the monotypic genus Labrichthys. The generic name combines the Greek labrax, meaning 'voracious', and ichthys, meaning 'fish'; the specific name unilineatus means 'one lined', referring to the lateral stripe of juveniles.

Juveniles are brown with two bluish white stripes along the body, which disappear as they grow. Females are yellowish brown with faint stripes, while males are more intensely colored with a large yellow patch around the base of the pectoral fin. The yellow lips are thick and fleshy, forming a short tube when the mouth is closed. The head is covered in scales except for a sheath over the base of the upper lip, the area in front of the eyes, and the chin. The upper jaw has no teeth between the two forward pairs of canines and the large canine in the corner of each jaw.

The species occurs in lagoons and on coral reefs at depths from 0 to 20 m. It inhabits shallow lagoon reefs and semi-protected seaward reefs with high coral cover, especially near branching corals like staghorn corals of the genus Acropora, whose polyps are its main diet.

Reader's Guide

The tubelip wrasse is of minor importance to local commercial fisheries and occasionally appears in the aquarium trade. Its significance lies primarily in its unique morphology and monotypic status within the genus Labrichthys. The species has a wide Indo-Pacific distribution, ranging from the coast of East Africa (Tanzania and Mozambique) through the Indian Ocean, including the main islands, into the Pacific Ocean as far as Micronesia and Samoa, north to the Ryukyus and Taiwan, and south to the Great Barrier Reef and Lord Howe Island in Australia. Its specialized diet of coral polyps, particularly from Acropora species, ties it closely to healthy coral reef ecosystems. The tubelike lips, which give the species its common name, are a distinctive adaptation likely related to feeding on coral polyps. While not a major target for fisheries, its presence in the aquarium trade indicates some interest among hobbyists. The species' conservation status is not addressed in the source article, but its reliance on coral-rich habitats suggests vulnerability to reef degradation.

Did You Know?

• The tubelip wrasse is the only known member of its genus, Labrichthys.
• Juveniles have two bluish white stripes that disappear as they grow.
• Its diet consists mainly of polyps from staghorn corals of the genus Acropora.