The yellowtail tubelip , Diproctacanthus xanthurus, is a species of wrasse native to coral reefs of the western Pacific Ocean. It can be found at depths from 3 to 25 m (9.8 to 82.0 ft). The juveniles act as cleaner fish, while the adults primarily prey on coral polyps. This species grows to a total length of 10 cm (3.9 in). It can be found in the aquarium trade. This species is the only known member of its genus.