The Eritrean butterflyfish or Crown butterflyfish or Redbacked butterflyfish, Chaetodon paucifasciatus, is a member of the Chaetodontidae. Indian Ocean: apparently confined to the Red Sea and the Gulf of Aden, but has been reported from East Africa.
The Eritrean butterflyfish grows up to 14cm in length. It is white with black chevrons except for a red bar stretching from the dorsal fin, across the tail to the top of the anal fin. They are oviparous fish forming monogamous pairings during breeding. They feed on coral polyps, gorgonians, algae, polychaete worms and small crustaceans. Eritrean butterflyfish are usually found in pairs or in small groups over coral and rubble areas from 1m to 30m depth. (text source: Wikipedia)