Japan Surgeonfish

Acanthurus japonicus has a laterally compressed oval body with long based dorsal and anal fins. 9 spines and between 28 and 31 soft rays support the dorsal fin while the anal fin is supported by 3 spines and between 26 and 29 soft rays. The colour of this fish varies with the emotional state of the fish and may be brown, diffused with blue through to almost yellow but its most notable feature is a wide white band extending from the lower part of the orbit to the upper lip. There is a pink band along the soft-rayed part of the dorsal fin. The caudal peduncle is black with a yellow base. The caudal fin is truncate and the pectoral fins have yellow bases.

This species has a maximum published total length 21 cm (8.3 in).

Acanthurus japonicus is found in the Western Pacific Ocean from southern Japan south to Sulawesi in Indonesia. This species occurs in small schools at depths between 1 and 20 m (3 ft 3 in and 65 ft 7 in) in clear water on lagoon and seaward reefs.