Geographic variability in the gonadal development and sexual ontogeny of <scp> <i>Hemigymnus</i> , <i>Cheilinus</i> </scp> and <scp> <i>Oxycheilinus</i> </scp> wrasses among <scp>Indo‐Pacific</scp> coral reefs

Patterns of reproductive ontogeny in four species coral reef wrasses (F: Labridae) Hemigymnus melapterus, fasciatus, Cheilinus fasciatus and Oxycheilinus digramma were investigated. Populations each sampled from two island groups the central Great Barrier Reef (GBR), Australia, reefs Philippines. These three sampling locations span 30° latitude. The GBR Philippine experience biologically significant differences water temperature, geography human activity. studied are effectively unfished Australia but heavily fished Gonad weights, histology demographic data obtained across entire size age range H. C. O. all locations. Analysis identified processes male recruitment: functional gonochorism both forms protogynous hermaphroditism, monandry diandry. expression these distinct sexual ontogenies was locality dependent. on showed consistently uniform patterns ontogeny, with being exclusively monandric. Philippines displayed complex ontogenies, showing histological evidence diandry gonochorism. Reproductive investment gonadal tissue, population sex structure, also differed between reefs. populations had substantially lower gonado-somatic indices than GBR. Nonetheless, matured more rapidly a protracted timing change over large range. Thus, mature females appeared earlier persisted later into Protracted is likely linked to presence primary males population, which known reduce strength selection for undergo become male. Hypotheses based social structure fish populations, environmental factors evolutionary history developed account different focal wrasses.