, ▁and ▁Egypt ▁. ▁Its ▁natural ▁habitat ▁includes ▁open ▁se as ▁and ▁cor al ▁re ef s . ▁Cor al ▁tr out ▁move ▁around ▁consider ably ▁within ▁a ▁single ▁re ef , ▁though ▁often ▁no ▁further ▁than ▁ ▁from ▁it . ▁Mov ement ▁between ▁neighbor ing ▁re ef s ▁does ▁not ▁occur ▁to ▁a ▁large ▁extent ; ▁however , ▁a ▁few ▁cases ▁have ▁been ▁reported ▁where ▁fish ▁have ▁moved ▁from ▁one ▁re ef ▁to ▁another . ▁Much ▁of ▁this ▁movement ▁may ▁be ▁the ▁result ▁of ▁fish ▁moving ▁towards ▁or ▁away ▁from ▁sp aw ning ▁sites . ▁ ▁Re production ▁ ▁Document ing ▁the ▁size ▁and ▁age ▁structures ▁during ▁reprodu ction ▁of ▁cor al ▁tr out ▁stock s ▁have ▁been ▁a ▁focus ▁of ▁the ▁EL F ▁experiment ▁as ▁a ▁major ▁indic ation ▁of ▁how ▁fish ▁stock s ▁respond ▁to ▁various ▁levels ▁of ▁fish ing ▁pressure . ▁ ▁Like ▁many ▁ ▁Ser ran idae , ▁cor al ▁tr out ▁are ▁prot og yn ous ▁herm aph rod ites . ▁They ▁start ▁their ▁lives ▁as ▁females , ▁and ▁change ▁sex ▁later ▁in ▁life . ▁The ▁trigger ▁of ▁this ▁sex ▁change ▁is ▁unknown . ▁On ▁average , ▁sex ▁change ▁occurs ▁when ▁fish ▁are ▁between ▁ ▁in ▁length ; ▁the ▁average ▁length ▁at ▁sex ▁change ▁is ▁. ▁This ▁is ▁believed ▁to ▁happen ▁most ▁frequently ▁in ▁the ▁months ▁immediately ▁following ▁sp aw ning . ▁ ▁EL F ▁research ▁has ▁determined ▁that ▁the ▁sex ▁ratio ▁diff ers ▁in ▁different ▁areas ▁of ▁the ▁Great ▁Bar rier ▁Re ef , ▁and ▁may