Millet butterflyfish stripe runs from above the eye to the base of the operculum, and there is a large black patch on the caudal peduncle. This fish is endemic to the Hawaiian Islands and the Johnston Atoll, and is found down to depths of at least . Its habitats include coastal fringing reefs, outer reefs and lagoons. The millet butterflyfish is a schooling species found in mid-water that feeds on zooplankton. It also feeds opportunistically on polychaete worms and other small invertebrates on the seabed. Food is drawn into the mouth by rapid suction. It does not seem to be territorial but
Pethia cumingii at the base of the caudal peduncle posterior to base of anal. Both blotches are widest at the lateral line. Eye pale yellow or white. Dosal and ventral orange, with two horizontal rows of 5-7 black spots on dorsal which has a black tip to its anterior spine. Remaining fins yellow (Daraniyagala,1952).Dorsally olive, the side being silvery with a golden sheen. There are two vertically elongate blotches rather larger than the eye, one above the anal fine and the other above and behind the operculum. The dorsal and pelvic fines have yellow (Daraniyagala,1952 / Pethiyagoda 1991). Fins. D II.8, A