Pacific Ocean: Christmas Island in the eastern Indian Ocean to the Pitcairn Group.

Males often confused with S. tricolor. Juveniles and females distinct in their markings on the sides. Scales large. 6-7 median predorsal scales; 3 scale rows on cheek, ventral row with 2-6 scales (usually 3-4). Caudal fin slightly to moderately emarginate in initial phase; deeply lunate in terminal male. Dental plates partially covered by lips. Terminal males and some large initial-phase fish with 1 or 2 canines posteriorly on upper dental plate.

Often found on exposed outer lagoon and seaward reefs, usually in rich coral habitats. Generally solitary.