• The Korean Journal of Malacology
• /
• v.4 no.1
• /
• pp.1-16
• /
• 1988

The authors observed histochemical and ultrastructural characters on the osphradium of Rapana venosa Valenciennes using light microscope, scanning and transmission electron microscpes. The results were as follows:1)The basic structure of osphradium was bipectinated shape, which consisted of a septum situating in the center of osphradium and numerous osphradial leaflets. On the other hand, Epidermis of ospradial leaflets formed the structure of pseudostratified ciliated columnar epithelium which was composed of an epithelial cell layer, a basal cel layer and a neuropile. 2) Ciliated dpithelial cells:A large number of these cells were observed on the lateral and ventral regions but a small number of them were observed on the dorsal region. These cells had cylindrical microvilli, slender mitochondria and serve fibers.3) Supporting cells: These cells had cylindrical microvilli, spongy layer, electron dense granules, mitochondria and nerve fibers4) Four types secretory epothelial cells: Four distinct types of secretory epithelial cells were recognized and were arbitrily designated as Type I, Type II, Type III and Type IV.cell type I: These cells contained electron denwe granules(diameter, 0.94-1.56${\mu}{\textrm}{m}$), well developed Golgi apparatus and rough endoplasmic reticula, cell type II: These cills contained two types of granules of the different electron density. One was high electron density granules which were 0.4-1.0${\mu}{\textrm}{m}$ in diameter, The other was low electron density granules which were 0.75-1.2${\mu}{\textrm}{m}$ in diameter.cell type III:These cells had fibrous secretory materials and exhibited strongly positive reaction with Toluidine blue.cell type IV:A large number of this type of cells were observed on the ventral region of ospgradial leaflets and positively reacted with periodic acid Schiff reagent. 5)Dark cells contained several electron dense cillaty rootlets and unmerous granules but cellular organelles were not observed.6) Four types basal cells: Four distinci types of basal cells were recognized and arbitrarily designated as Type I, Type II, Type III and Type IV.Cell type I(light cell): These cells exhibited low electuon density and contained short smooth endoplasmic reticula, several vacuoles and granules.

• Development and Reproduction
• /
• v.17 no.1
• /
• pp.25-35
• /
• 2013

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.

• Journal of The Korean Society of Clinical Toxicology
• /
• v.15 no.1
• /
• pp.65-67
• /
• 2017

Even though Neptunea contricta appears similar to Batilus cornutus and Rapana venosa, they are different in tetramine content which inhibits the neuronal calcium channel. Therefore, mistaking Neptunea contricta for Batilus cornutus or Rapana venosa, can result in the occurrence of toxic symptoms. Three patients developed nausea, epigastric pain, chest pain, dizziness, blurred vision, dyspnea, hypertension and tachycardia after eating Neptunea contricta. Moreover, consumption of one only piece was sufficient to cause symptoms because each Neptunea contricta has 17.3 mg of tetramine. Accordingly, care should be taken when patients are consuming more than 5 pieces because toxic symptoms such as dyspnea can occur. Moreover, correct species identification is important because the quantity of tetramine varies among sea snail species. Finally, it is important to educate people to remove the salivary glands completely before consuming Neptunea contricta.

• The Korean Journal of Malacology
• /
• v.12 no.2
• /
• pp.85-90
• /
• 1996

3종의 복족류(Rapana venosa, Reishia bronni, Anthosiphonaria sirius)와 1종의 다판류, Lepidosona(Lepidosona) coreanica에 대한 18S ribosomal DNA의 염기서열을 밝히고 이들을 이미 보고된 18종의 이매패류, 2종의 복족류 그리고 1종의 다판류의 염기서열과 비교분석하였다. 그 셜과 복족류는 V4 region에서 다른 연체동물과 구별되는 독특한 inseerted sequinces를 가지고 있었으며, V2 region에서 복족류(Prosobranchia와 Pulmonata)와 이매패류(Pteriomorphia 와Heteerodonta) 각각의 두 아강들이 서로 다른 특징적인 insertions 또는 deletions으로 구분되었다.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.46 no.2
• /
• pp.126-138
• /
• 2010

To investigate seasonal variation of fisheries resources composition and their correlationships with environmental factors in the coastal ecosystem of the middle Yellow Sea of Korea, shrimp beam trawl were carried out for the fisheries survey. Fisheries resources of 81 species, 57 families, and 6 taxa totally were collected by shrimp beam trawl in the middle coastal ecosystem of Yellow Sea of Korea. Species were included 6 species in Bivalvia, 6 in Cephalopoda, 22 in Crustacea, 2 in Echinodermata, 5 in Gastropoda, and 40 in Pisces. Diversity indices (Shannon index, H') showed seasonal variation with low value of 2.14 in winter, and high value of 2.67 in spring. Main dominant species were Oratosquilla oratoria, Octopus ocellatus, Acanthogobius lactipes, Cynoglossus joyneri, Rapana venosa venosa, Loligo beka, Chaeturichthys stigmatias, Raja kenojei, Microstomus achne and Paralichthys olivaceus, that were occupied over 58% of total individuals, and 55% of wet weight. Fisheries organism made four coordinative seasonal groups by the principal component analysis (PCA), showing stronger seasonal variation than spatial variation. PC from PCA showed statistically significant cross-correlationships with seawater temperature, $NH_4$-N, TP and chlorophyll a (P < 0.05).

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• v.49 no.2
• /
• pp.106-115
• /
• 2013

A series of fishing experiments were carried out in the western coastal waters of Korea from May, 2006 to September, 2007, using gill nets of different mesh sizes (m=101, 121.8, 152.5, 176.8, and 191 mm) to determine the mesh selectivity of gill net for swimming crab, Potunus trituberculatus. The catch species was composed of swimming crab (87%), Thomas's rapa whelk Rapana venosa (5%), arthritic neptune Neptunea cumingi (2%), Japanese swimming crab Charybdis japonica (2%), marbled sole Pleuronectes yokohamae (1%), pen shell Atrina pectinata, ocellate spot skate Okamejei kenojei, and so on. The carapace length (CL) of each swimming crab caught in the experimental nets was measured. Sponge crab (egg-bearing female crab) was appeared from the end of June to August in the coastal waters. The master selection curve was estimated by applying the extended Kitahara's method. The selection curve showed that the gill nets of larger mesh size allowed more crabs of small carapace size to escape. The optimum value (CL/m) was 0.645 and the CL/m was estimated to be 0.301, 0.354, 0.391, 0.422, and 0.450 when the retention probabilities were 0.1, 0.2, 0.3, 0.4 and 0.5, respectively.

• The Korean Journal of Malacology
• /
• v.32 no.2
• /
• pp.133-139
• /
• 2016

The incubation time required for hatching of O. ocellatus were investigated through the processes of egg and embryonic developments by the dissecting microscopic and visual observations. And differences in ecological characteristics of the plankton mode of life or the benthic mode of life according to total numbers of the suckers on each short arm of the hatched juvenile larvae of O. ocellatus were studied by comparisons with other octopodidae species. Compared with the recent a few results reported by other researchers associated with the incubation time required for hatching by female adult mother of O. minor (73-90 days after spawning at $20.9-21.5^{\circ}C$ ranges), in this study, the incubation time required for hatching by female adult mother of O. ocellatus was 56-57 days after spawning at $11.0-20.4^{\circ}C$. Therefore, the incubation time required for hatching by female adult mother varied with Octopodidae species. In this studies, each ovarian egg laid by a female was connected to an egg string attaching to the surface of the wall or bottom of vacunt shell of Rapana venosa. Egg and embryonic developments of this species were studied in the indoor aquaria, in the specific gravity ranging 1.024-1.025. the hatched juvenile of O. ocellatus is 10.3 mm in the mean total length and 4.5 mm in mantle length, and each of its short arms has 18-20 suckers. The just hatched juvenile larvae of O. ocellatus enter the benthic mode of life (benthic larval stage) after hatching. In particular, regarding differences in ecological characteristics of the mode of life according to total numbers of the suckers, O. vulgaris may not need to have many suckers because they enter the planktonic mode of life after hatching, however O. ocellatus may need to have many suckers, because they should adapt to the benthic mode of life. And also the just hatched juvenile larvae of O. minor (bearing many suckers more than O. ocellatus) enter the benthic mode of life (benthic larval stage) after hatching. Therefore, the total number of the suckers on each short arm of the hatched juvenile larvae can be used for determining whether an octopus species has planktonic larval stages or benthic larval stage (benthic mode of life). In particular, The intracohort cannibalism phenomena appeared at the hatched juvenile larval stage because the larval stage of O. ocellatus and O. minor enter into the benthic larval stage in the early stage, unlike entering into the plaktonic larval stage in other Octopus species such as O. vulgaris: at this time, the early hatched larvae fed the late hatched larvae (they are the same species and almost same ages). Therefore, the intracohort cannibalism pheneomena occur in the just hatched juvenile stage of only O. ocellatus and O. minor.

• Journal of fish pathology
• /
• v.18 no.1
• /
• pp.49-58
• /
• 2005

Hemacolor stain, histopathological observation and FTM incubation assay were applied to detect Perkinsus sp. infection in Manila clams (Ruditapes philippinarumi taken from culture beds at Tean and Gochang from March 2002 to August 2003. The prevalency was 100% in the clams from Gochang and 20-70% from Tean. Of the three methods, histopathological observation was the most effective to detect the infection. And the parasites was most abundant in gills. When PCR assay was applied to detect Perkinsus sp. for four species of Mollusc such as manila clam, surf clam (Mactra veneriformis), oyster (Crassostrea gigas) and Thomas' rapa whelk (Rapana venosa) taken from Tean and Gochang from April to July 2004, the parasites were detected from all the species at the infection rates of 95%, 62%, 46.9% and 10% in that order. The infection rate was much higher in the species burrowing in the bottom sediments than those attaching on the tidal rock. The results suggest that Perkinsus sp. may affect almost all the molluscs inhabiting western coastal areas of Korea.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.32 no.3
• /
• pp.303-309
• /
• 1999

Mass mortality of the Manila clam, Ruditapes philippinarum has been reported all along the west and south coast of Korea for the past several years. As a pathogenic agent, Perkinsus sp., an endoparasitic protozoan has been identified in this study and believed to be responsible for the mass mortalities. Prevalence and infection intensity of Perkinsus sp. was investigated from a Manila clam population inhabiting at Komsoe Bay in the west coast where mass mortality of the clam has been reported. A total of 142 Manila clam, 50 oyster, Crassostrea gigas, 10 ark shell, Scapharca broughtonii, and 5 predatory gastropada, Rapana venosa were examined for the presence and the quantity of Perkinsus sp. Ray's fluid thioglycollate medium method (FTM method) with modified Mackin's infection intensity scale and Choi's quantitative method were used in detecting and quantifying the parasite. All individuals of R. philippinarum examined in this study were infected with Perkinsus sp., indicating $100\%$ prevalence while none of the oysters and the gastropods exhibited the parasite. Six to ten individual hypnospores of Perkinsus sp. were counted from the ark shells. The number of hypnospores in the clam tissues varied from 16,667 to 4,091,667, with a mean number of 1,077,628. Average infection intensity according to Mackin's was 2.87, indicating a moderate infection. A negative correlation was observed between the number of Perkinsus sp. in the tissue and the condition index, a ratio tissue wet weight to shell cavity volume. The clam size and the infection intensity in terms of total number of parasites were positively correlated; the bigger clam, the heavier infection. Such high number of Perkinsus sp. counted in the clams could be enough to cause physiological disturbance of clams, such as retarded growth and reproduction. It is also believed that such a high infection leads mortality of the clam via continuous draining of the energy by metabolic activities and reproduction of the parasites. Correlation between the condition index and the infection intensity observed in this study supports this hypothesis.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.19 no.5
• /
• pp.446-452
• /
• 1986

This paper presents the composition of neutral and polar lipids obtained from puple shell, Rapana venosa and the abalone, Haliotis discus hannai. The fatty acid composition and the classification of neutral lipids from two species were determined by gas chromatography (GLC) and thin layer chromatography (TLC). Total lipid contents of samples were $0.5\%$ in purple shell and $0.4\%$ in the abalone. The predominant fatty acids of total lipids were eicosapentaenoic acid ($19.30\%$). eicosenoic acid ($12.10\%$) and palmitic acid ($11.77\%$) in the purple shell, and palmitic acid ($21.29\%$), oleic acid ($14.55\%$) and linoleic acid ($14.21\%$) in the abalone. The lipid composition of non-polar lipid fractions in purple shell and abalone was separated and identified as free sterol, free fatty acid, triglyceride and hydrocarbon & esterified sterol by TLC. The contents of triglyceride from both neutral lipids were shown more abundant than any other subclasses. The main fatty acids of neutral lipids were eicosapentaenoic acid ($18.6\%$), palmitic acid ($14.90\%$) and eicosenoic acid ($14.76\%$) in the purple shell, and palmitic acid ($28.12\%$), oleic acid($20.5\%$) and myristic acid ($12.5\%$) in the abalone. Eicosapentaenoic acid ($17.57\%$), stearic acid ($13.26\%$) and eicosatetraenoic acid ($11.24\%$) were important fatty acids of glycolipid in the purple shell, and myristic acid ($12.75\%$), stearic acid ($12.10\%$) and eicosatetraenoic acid ($10.64\%$) in the abalone. The major fatty acids of phospholipids were eicosapentaenoic acid ($20.18\%$), palmitic acid ($11.26\%$) and eicosenoic acid ($10.90\%$) in the purple shell, and palmitic acid ($21.10\%$), eicosapentaenoic acid ($12.90\%$) and oleic acid($11.13\%$) in the abalone.