Author : Munasik

Summary : This study was designed to investigate the reproduction period, reproductive effort and recruitment rate of coral Pocillopora damicornis in southern and northern sides of Panjang Island, Central Java. Reproduction period was determined by observing gametogenesis, embryogenesis and planulation (planulae release) period, while the reproductive effort was estimated by measuring polyp fecundity and larval production in each colony. Recruitment rate of the coral was determined by the density of juvenile in the field. The results showed that reproductive effort and recruitment rate of coral P. damicornis between southern and northern sides of Panjang Island was different. Reproduction period was not different between the sides while reproductive activities occurs every month throughout the year. The multiple gametogenic cycles resulted double peaks planulation in a single colony while planulation in paired colony revealed single peak, indicated that variation in planulation period due to adaptation of gametogenic cycles which controlled by the existence of other colonies. Reproductive effort varied seasonally with increasing the polyp fecundity and larval production in southeast monsoon and decreasing in northwest monsoon. The annual fluctuations in reproduction was controlled by the interaction of water temperature, fotoperiod (day length), nutrien, and rainfall. High larval production in southern side and which trapped by the turbulent eddies current caused high recruitment in the side however the side revealed low in survival rate of juvenile. Recruitment was characterized by high mortality of juvenile in the early settlement period and high abundance of juvenile under surfaces of settlement plates which influenced by sediment accumulation. High recruitment occurred around their parental colonies seems to corresponding with the adult distribution. It is suggested that coral P. damicornis maintained the population by internal recruitment.