• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1997.06a
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• pp.167.1-168
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• 1997

• The Korean Journal of Malacology
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• v.9 no.2
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• pp.1-15
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• 1993

The reproductive ecology of the purple shell, Rapana venosa was investigated by the histological observations on depositions of the egg capsules, and hatching of larvae in the laboratory and the subtidal zone of the vicinity of piung-do, Chollabud-do, west coast of korea, for one year from June 1992 to May 1993. The results are summarized as follows:1. Rapana venosa is dioecious in sex. The ovary is composed of a number of ovarian lobules, and the testis comprises a number of ovarian lobules, and the testis comprises of gonads could be classified into 4 stages in males and 5 stages in females: 1) growing stage(in female subdivided into 2 stages of early and late growing stage). 2)mature stage. 3)spent stage or copulationstage. 4)rdcovering stage. The early growing stage in females of the purple shell was in September through February, late gorwing stage was in October to March, mature stage was in September to January, mature stage was in September to July, copulation stage was in Februaty to June and recovering stage in April to October.3. Spawning occurred 3-4 times at intervals of 1-3 days, and completed within 10 days from the beginning of spawning during the spawning season of the year.4. From the results of laboratory and field observations, egg masses are composed of a number of egg capsules, egg masses are occurred from May to late August, and in mid August depositions of egg mass in composed of 90-113 egg capsules, fecundity in an egg capsule was ranged 984 to 1,241 eggs(average 1,096 egg). Therefore, fecundity in total egg capsules spawned per individual during the spawning season is estimated as approximately 320,000 to 450,000 egges.5. The incubation period during deposition of an egg capsule to hatching larvad tood 17 days at 18.3-20.4%C(water temperature)and 1.021 (specific gravity fo sea water).

• Development and Reproduction
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• v.6 no.1
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• pp.37-44
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• 2002

First sexual maturity, sex ratio, spawning frequency, deposition of the egg capsules and fecundity of the female Rapana venosa(Valenciennes) inhabited in the artificially closed slag deposit area, Gwangyang Bay were investigated by histologicai and visual observations for natural living resource management. The rate of individuals reaching the first sexual maturity was 51.6％ in females measuring 7.1~8.0 cm in shell height, and 100％ in those > 10.1 cm. The total number of egg capsules per individual and the mean number of eggs in an egg capsule were 192~382 and 500, respectively. However, the number of eggs per individual and sizes of egg capsules under lower salinity and deficient food conditions in the closed slag deposit area were smaller than those under the optimum salinity and sufficient food conditions in the open regions. Fecundities of the species were approximately from 96,000 to 191,000 eggs/individual with two to low broods(spawning frequencies) during the spawning season. The duration of development in egg capsules was 18~19 days at about 18~2$0^{\circ}C$. R. venosa is a species whose embryos hatch as veliger larvae, not juvenile snail. The sex ratio of female : male was not significantly different from 1 : 1($\chi$$^2$= 0.23, p>0.05).

• The Korean Journal of Malacology
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• v.31 no.1
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• pp.9-19
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• 2015

Germ cell development and cyclic changes in the epithelial cells of the seminal vesicle of the male rapa whelk, Rapana venosa, were investigated by cytological and histological observations. The process of germ cell development can be classified into five stages: (1) spermatogonial, (2) primary spermatocyte, (3) secodary spermatocyte, (4) spermatid, and (5) spermatozoon. In particular, four atypical cells (Type IA, IB, IIA and IIB cells) occur among normal germ cells in the acini during spermatogenesis. Presumably, the atypical cells, which have lysosome-like vacuoles or lysosome-like bodies in the cells, are involved in breakdown and absorption themselves in the acini. However, atypical cells were not found in the epithelial cells of the inner layer of the seminal vesicle. A considerable amount of spermatozoa are transported from the testis towards the the seminal vesicles until late July. The main coupulation period is between June and July. The process of the cyclical changes of the seminal vesicles can be classified into three phases: (1) resting, (2) accumulating, and (3) spent. Yellow granular bodies are involved in resorption or digestion of residual spermatozoa.

• Journal of Fisheries and Marine Sciences Education
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• v.27 no.4
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• pp.1031-1040
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• 2015

Ultrstructural studies of germ cell differentiation and vitellogenesis in the oocytes of the female Rapana venosa in the brackish water area of Seomjin River were investigated by transmission electron microscope observations. In the early vitellogenic oocytes, the Golgi complex and mitochondria were involved in the formation of glycogen particle, lipid droplets, and yolk granules. In the late vitellogenic oocytes, the rough endoplasmic reticulum and multivesicular bodies were involved in the formation of proteid yolk granules in the cytoplasm. However, heterosynthetic vitellogenesis in this species were not observed in vitellogenic oocytes during oogenesis. A mature yolk granule was composed of three components: crystalline core, electron lucent cortex and the limiting membrane. As shown in some large gastropods, vitellogenesis in R. venosa occurred by way of endogenous autosynthesis without heterosythetic vitellogenesis (exogeneous endocytosis), which are found in the oocytes in bivalves. The mating period and spawning activity were related with the increases of seawater temperatures and salinities.

• Proceedings of the Malacological Society of Korea Conference
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• 2002.11a
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• pp.6-6
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• 2002

• The Korean Journal of Malacology
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• v.30 no.2
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• pp.139-153
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• 2014

We investigated fecundities in egg capsules and sizes at 50% of group sexual maturities in female Rapana venosa in three different salinity concentration regions (S-1, S-2, and S-3). In three different salinities, egg capsule heights, the number of egg capsules and the number of eggs and embryos were remarkably increased with the increase of female shell heights (or ages) and also increased with the increase of salinity concentrations. Heights of egg capsules, the number of egg capsules and fecundities (the number of eggs and embryos) were the maximum at S-1 (Gwangyang Bay (average 31.5 psu)) and the minimum at S-3 (the upper reaches of Seomjin River (average 15.5 psu)). Total numbers of fecundities of R. venosa $individual^{-1}year^{-1}$ were about $1{\times}10^6$ at S-1 region, about $8{\times}10^5$ at S-2 region, and about $2{\times}10^5$ at S-3 region. Rates (50%) of individuals reaching first sexual maturities in three different salinity regions (S-1, S-2 and S-3) were over 50% in females measuring 7.1-8.0 cm in shell height (considered to be two years old), and 100% in those > 10.1 cm (considered to be five years old). Biological minimum sizes ($RM_{50}$) in females in three different regions are 72.0 mm SH at S-1 region, 70.9 mm SH at S-2 region, and 74.6 mm SH at S-3 region, respectively. Exceptionally, smaller individuals (considered to be one year old) were participated in reproduction.

• The Korean Journal of Malacology
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• v.25 no.3
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• pp.189-196
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• 2009

Based on 1,260 samples, the age and growth of purple whelk, Rapana venosa (Valenciennes) (Gastropoda:Muricidae) have been investigated. The samples were collected monthly during one year time (from February, 2004 to January, 2005) from the West Sea of Korea. The age of R. venosa was determined by the ring of the operculum analysis. The relationship between whelk's shell height and ring radius in each ring group was expressed as an equation of linear regression and later a correspondence in each ring formation was determined. Based on the monthly variations in the marginal index (MI) of the operculum, it was assumed that the ring of this species has been formed once a year during the period from July to August. The relationship between shell height and shell width was expressed by the equation SW = 0.7867 SH - 6.3988 ($R^2$=0.8604); and between shell height and total weight by the equation $TW=0.0000626{\times}SH^{3.206}$ ($R^2$=0.8324). The purple whelk's spawning period was estimated through the fatness analysis and has occurred during the period from May to July. Obtained results suggests that the ring formation occurs once a year (in July) and the length of time period since the first ring has been formed on the operculum is approximately 13 months (1.08 year). The purple whelk's growth curves for shell height and total weight fitted to the von Bertalanffy's equation and were expressed as follows: $SH_t=199.653(1-e^{-0.104(t+2.478)}$ $TW_t=1484.105(1-e^{0.104(t+2.478)})^{3.206}$.

• The Korean Journal of Food & Health Convergence
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• v.4 no.3
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• pp.22-31
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• 2018

In this present work, the amounts of toxic elements were determined in the soft tissues of mollusks (Mytilus galloprovincialis and Rapana venosa) collected from Igneada shores of the Black Sea where suggested as Marine Protection Area (MPA). M. galloprovincialis accumulated the highest amounts of Cd in winter, while the highest amounts of Cd and Hg were detected in R. venosa in winter and autumn. The concentrations of toxic elements found in the soft tissues of mollusks varied for Cd: 0.07-0.14, Hg: 0.03-0.44 and Pb: 0.09-0.21 mg/g dry wt. The estimated levels of all non-essential metals in the present work were lower than the limits permitted by European Community Regulation (EU) and the Turkish Food Codex (TFC). The estimated weekly intakes (EWI) and daily intakes (EDI) of all the through consumption of these seafood by Turkish people in the Igneada coasts of the Black Sea were quite below the permissible tolerable weekly/daily intakes for 70 kg person (PTWI / PTDI) set by FAO/WHO. As results, it can be concluded that no hazard effects on people health would be raised at present from the consumption of these mollusks' species.

• The Korean Journal of Malacology
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• v.17 no.1
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• pp.27-33
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• 2001

The Ovarian developmental phases of the reproductive cycle of Rapana venosa can be classified into five successive stages by histological study: early active stage (September to February), late active stage (December to April), ripe stage (March to July), partially spawned stage (May to August), and recovery stage (June to September). To understand the characteristics of nutrient storage and utilization in the digestive gland cells with ovarian developmental phases, we examined the digestive gland - which is the major nutrient supply organ associated with ovarian development of the female purple shell - by biochemical methods. Total protein contents in the digestive gland tissues increased in March (late active stage) and reached the maximum in May (ripe and partially spawned stages), and then their levels sharply decreased in July (partially spawned and recovery stages). Total lipid contents in the digestive gland tissues reached the maximum in January (early active stage). Thereafter, their levels rapidly decreased from May (ripe and partially spawned stages) and reached a minimum in July (partially spawned and recovery stages). The total DNA contents did not significantly change regardless of the different developmental stages of the ovary. However, it was also found from biochemical analysis that changes in total RNA content follow the same seasonal cycling to protein. These results indicate that the digestive gland is an important energy storage and supply organ in purple shells, and that the nutrient contents of the digestive gland change in response to gonadal energy needs.