▁once ▁regarded ▁as ▁w ides p read ▁in ▁the ▁Indian ▁Ocean , ▁now ad ays ▁the ▁Indian ▁Ocean ▁form ▁is ▁regarded ▁to ▁be ▁Ce phal oph olis ▁n ig rip inn is ▁( C ra ig ▁and ▁H ast ings ▁ 2 0 0 7 ). ▁ ▁Description ▁ ▁The ▁V - tail ▁Gr ou per ▁is ▁a ▁medium ▁size ▁fish ▁and ▁can ▁reach ▁a ▁maximum ▁size ▁of ▁ 2 8   cm ▁length . ▁The ▁basic ▁body ▁color ▁is ▁re dd ish ▁brown , ▁with ▁two ▁white ▁diagonal ▁bars ▁on ▁the ▁ca ud al ▁fin . ▁The ▁back ▁half ▁of ▁the ▁body ▁usually ▁is ▁dark er ▁and ▁shows ▁a ▁few ▁faint ▁trans vers al ▁bars . ▁ ▁Bi ology ▁These ▁fish es ▁mainly ▁feed ▁on ▁small ▁fish es ▁and ▁cr ust ace ans . ▁ ▁Distribution ▁The ▁Flag tail ▁Gr ou per ▁is ▁w ides p read ▁throughout ▁the ▁tropical ▁waters ▁of ▁the ▁Ind o - P ac ific ▁area , ▁occurr ing ▁east ward ▁to ▁French ▁Pol yn esia ▁and ▁the ▁Pit ca ir n ▁Islands , ▁and ▁on ▁Christmas ▁Island , ▁Red ▁Sea ▁ex cluded . ▁ ▁Hab itat ▁Ce ph ap lo ph olis ▁u rod eta ▁can ▁be ▁found ▁in ▁cor al ▁re ef s ▁and ▁l ago ons ▁and ▁pre fers ▁shall ow ▁waters ▁to ▁depth s ▁of ▁about ▁. ▁ ▁Bibli ography ▁ ▁Rand all , ▁J . E . ▁and ▁P . C . ▁He em stra ▁( 1 9 9 1 ) ▁Re vision