Pacific Ocean: Christmas Island and offshore reefs of northwestern Australia in the eastern Indian Ocean to the islands of Oceania (excluding the Hawaiian Islands).

Fish exhibit color variation with size and location. Juveniles are slate gray to a brilliant metallic blue with a bright orange-yellow tail. Adults are dark gray to black, and in most areas have a white tail.

Found in steep outer reef slopes and shallow coastal reef flats, sometimes forming large aggregations feeding on zooplankton several meters above the bottom. Juveniles remain close to shelter. Nests in small patches of loose sand under ledges or at the base of slopes.