title: The Effects of Female Shell Size on Reproductive Potential of the Egg Capsule in Rapa Whelk Rapana venosa in Three Regions of Different Salinities.
abstract: We investigated the effects of shell height on reproductive potential of the female Rapana venosa in three regions of different salinities (the coastal zone of the Gwangyang Bay (S-1); the upper reaches (S-3); lower reaches (S-2) of the Seomjin River). The number of egg capsules, egg capsule height, and fecundity associated with reproductive potential of larger female rapa whelks were higher than those of smaller individuals in all three regions. Correlation analyses showed that there is a significant positive correlation between egg capsule and female shell height. Mean of shell heights, egg capsule heights, the number of egg capsules in an egg mass, and fecundity in an egg capsule produced from female individuals inhabiting S-1 region were markedly higher than those inhabiting S-2 and S-3 regions. In particular, the fecundity of the rapa whelk increased with the salinity and shell height. Although large rapa whelks produced a large number of egg capsules at S-1 region, those at S-3 habitat laid less egg capsules with smaller size. If these rapa whelks were put into S-2 region, the number of egg capsules produced by a female at S-2 region was slightly larger than those produced by a female at S-3 region. This provides a clear evidence that the number of the egg capsules can be controlled by the salinity. In the coastal zone of the Gwangyang Bay and the upper reaches of Seomjin River, the fecundity of this species was estimated to be approximately 182,000-1,302,000 eggs/ind./yr.
authors.affiliation: Department of Marine Biotechnology, Kunsan National University, Gunsan 573-701, Korea.
authors.forename: Ee-Yung
authors.initials: EY
authors.lastname: Chung
authors.affiliation: Department of Aquatic Life Medicine, Kunsan National University, Gunsan 573-701, Korea.
authors.forename: Kwan Ha
authors.initials: KH
authors.lastname: Park
authors.affiliation: Institute of Environmental Protection and Safety, Neoenbiz Co. Bucheon 420-806, Korea.
authors.forename: Chang-Hoon
authors.initials: CH
authors.lastname: Lee
authors.affiliation: Sea Green Industry Institute, Bucheon 420-851, Korea.
authors.forename: Young Jae
authors.initials: YJ
authors.lastname: Park
keywords: Correlation analysis; Egg capsule; Fecundity; Rapana venosa; Reproductive potential