Blue Blanquillo

The blue blanquillo has an elongated body with a pointed snout, the mouth reaching as far as the forward nostril. The margin of the preoperculum is smooth and the Gill cover has a sharp spine which is similar in size to diameter of the pupil. The head and anterior part of the body are blue, this colour fades posteriorly. There is a wide black lateral stripe which starts from the base of the pectoral fin in adults and from the snout in juveniles. The adults have fine lattice patterning on their upper back with a white area on the middle of the rear margin of the caudal fin. There is a pale line along upper margin of the greyish dorsal fin, the anal and pelvic fins are white while the pectoral fins are bluish. The juveniles resemble the juveniles of the ringed slender wrasse (Hologymnosus annulatus). The dorsal fin of this species contains 3–4 spines and 43–47 soft rays while the anal fin has 1 spine and 37–40 soft rays. It attains a maximum total length of 45 cm (18 in) although 35 cm (14 in) standard length is more typical.

The blue blanquillo has an Indo-Pacific distribution. It is found in the Red Sea and along the eastern coast of Africa, across the Indian Ocean and into the Pacific Ocean as far as the Hawaiian Islands, Tabuaeran and Samoa. It occurs north to Japan and south to Australia. In Australia their range extends from Dirk Hartog Island in Western Australia to Ashmore Reef in the Timor Sea and the Great Barrier Reef off Queensland south as far as Seal Rocks. This species also occurs at the Cocos (Keeling) Islands and Christmas Island.