Bluespot Butterflyfish

It has a bright yellow body which is marked with a large horizontal, elongated blue patch on the flanks above the midline. There is a black spot with bluish white margins on the caudal peduncle and a vertical black band which also has bluish white margins running through the eye. The dorsal, anal, pelvic and caudal fins are brilliant yellow. The juveniles lack the blue patch on the flanks. The dorsal fin contains 13–15 spines and 16–18 soft rays while the anal fin has 4–5 spines and 14–16 soft rays. This species attains a maximum total length of 15 centimetres (5.9 in).

The blueblotch butterflyfish is found in the western Pacific Ocean and the eastern Indian Ocean. It ranges from Vietnam east to Fiji, north to southern Japan and south to Australia. It is largely absent from Indonesia except from northern Papua. In Australia this species is found from Rottnest Island in Western Australia north to the Dampier Archipelago, it is then found from the northern Great Barrier Reef south as far as Arrawarra Headland near Coffs Harbour in New South Wales. It can also be found on the Coral Sea reefs, Elizabeth Reef, Middleton Reef and Lord Howe Island in the Tasman Sea.