• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.109-117
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• 1986

For the purpose of obtaining basic data which can be applied to processing of retort pouched shellfishes, retort pouched seasoned ark shell, Anadara broughtonii, was prepared. The frozen ark shell was thawed and seasoned with a mixed seasoning powder prepared with $10.0\%$ of sorbitol, $2.0\%$ of table salt and $0.5\%$ of monosodium glutamate at $5^{\circ}C$ for 10 hours, and then dried at $45^{\circ}C$ for 4 hours. The dried seasoned ark shell was coated with $1.0\%$ sodium alginate solution, dried with cola air blast for 2 hours and then vacuum-packed in the laminated plastic film bag (polyester/casted polypropylene= $12{\mu}m/70{\mu}m,\;15{\times}16cm$), and finally sterilized up to Fo=6.0 in hot water circulating retort at $121^{\circ}C$ for 10 minutes. The major fatty acids of raw ark shell and retort pouched seasoned ark shell products were 16:0, 20:5, 22:6, 18:0 and 18:3, and predominant free amino acids of those were lysine, arginine, glycine, alanine, glutamic acid and leucine. In nucleotides and its related compounds of raw ark shell and retort pouched seasoned ark shell products, the most abundant one was AMP, and total extract-N of those was chiefly consisted of free amino acids, betaine and nucleotide and its related compounds. During the processing procedure such as drying and sterilization, unsaturated fatty acids slightly decreased while saturated fatty acids increased, and total extract-N content decreased about a half. From the results of chemical and microbial experiments during storage, it was concluded that the products could be preserved in a good condition for 100 days at room temperature, and their duality could be improved by the coating treatment of sodium alginate solution.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.3
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• pp.171-175
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• 1992

In 1991, specimens of the arkshell, Scapharca broughtonii of Arcidae(Ptriomorphia, Mollusca) were collected from bottom culture bed at Namhae Island in Korea. The chromosomes were examined in the colchicinetreated cells of trochophore larva based on the air-drying method. Diploid number of the chromosome was 38 which were classified as metacentrics(pairs 5, 8, 13), meta or submetacentrics(pairs 6, 7), submetacentrics(2, 3, 9, 10, 12, 15, 16, 17, 18, 19) and subtelocentrirs(pairs 1, 4, 11, 14). No telocentric chromosome was observed.

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.149-155
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• 2016

To assess the effects of environmental factors on the sustainability of cultured ark shell Scapharca broughtonii production, we investigated the habitat characteristics of shellfish-farming bays (Gangjin Bay, Yeoja Bay, Keoje Bay and Deukryang Bay). We measured the physiochemical parameters (temperature, salinity, dissolved oxygen, nutrients, chemical oxygen demand and Chlorophyll a) and the geochemical characteristics (chemical oxygen demand, ignition loss, C/N ratio and C/S ratio). Surface sediments were collected from several shellfish-farming bays to examine the geochemical characteristics of both the benthic environment and heavy metal pollution. The grain sizes for Gangjin Bay, Yeoja Bay and Keoje Bay were similar, at the ratio of silt and clay in comparison with Deukryang bay of it. The C/N ratio was more than 5.9, reflecting the range arising from the mix of marine organisms and organic matter. The C/S ratio (more than 4.2) showed that the survey area had anoxic or sub-anoxic bottom conditions. The index of accumulation rate (Igeo) of the metals showed that those research areas can be classified as heavily polluted, heavily to moderately polluted, or more or less unpolluted, respectively. We suggested that the growth of ark shell Scapharca broughtonii in the shellfish-farming bay was effected by the various environmental conditions.

• The Korean Journal of Malacology
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• v.28 no.3
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• pp.269-274
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• 2012

The genetic variation of Ark Shell, Scapharca broughtonii black was estimated using six polymorphic microsatellite (MS) loci in 443 individuals collected from five populations in Korea. The mean numbers of alleles per locus in five populations were 10-28. The mean number of alleles per locus in Jinhae Hatchery (JHH) population showed the least value as 15.5, but that in Gangjin (GJ) population showed the most value as 20.3. The mean expected heterozygosity in Saryangdo (SR) population showed the least value as 0.817, but that in Gangjin (GJ) population showed the most value as 0.831. In Jinhae hatchery(JHH) population, the mean expected heterozygosity was 0.822, there was no significant difference from those of wild population. The $F_{ST}$ values in Gangjin (GJ) population showed significant difference from those of the other populations, which revealed Gangjin (GJ) population is genetically different from the other populations. The $F_{ST}$ values among Jinhae Hatchery (JHH) population, Jinhae (JH) population and Saryangdo (SR) population showed lower values than the others, which implies there was a gene flow among these three populations. The $F_{ST}$ value and genetic distance between Jinhae (JH) population and Saryangdo (SR) population showed the least value as 0.0001 and 0.0386, indicating that these two populations were genetically the same.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.24 no.1
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• pp.70-78
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• 1991

Both long period of summer drought and unusual high water temperature in 1988 caused the harmfull effect to the aquacultural organisms in south coast of Korea. One of those was the mass mortality of arkshell seedlings in Jinhae Bay. The purpose of this study was to verify the effects of environmental factors on arkshell seedlings by investigating not only water quality and food organisms in culturing grounds, but also meteorological conditions. Water temperature in November was higher at $2.0^{\circ}C$ than mean water temperature and the concentration of total inorganic nitrogen and N/P ratio were $0.38{\mu}g-at/l,$ 0.98, respectively which indicated the exhaustion of nutrients, especially nitrogen in the study area. In analysis of phytoplankton population structure, species diversity index(H) , equitability-index(e), species richness $index(d_1)$ were low, but dominance $index({\delta}_2)$ was high at the value of 98.4 and dominant species was Nitzschia pungens. In conclusion, it seems that mass .mortality of arkshell seedlings in November was resulted from the metabolism disorder with poor food organism under the unstable marine environment.

• Journal of Life Science
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• v.22 no.5
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• pp.642-649
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• 2012

The southern coast of Korea is important for the ark shell ($Scapharca$ $broughtonii$) aquaculture, but the productivity was rapidly reduced during the previous decade by mass mortality. To overcome this economic loss, investigations only focused on environmental factors, and microbiological researches were performed insufficiently. In this study, two sites (Gangjin and Jinhae bay) were selected for their high and low rate of mortality, respectively, and the existence of microflora from underwater sediments in the bodies of $S.$ $broughtonii$ was analyzed. We screened the whole body of each sample and chose unique colonies, which exhibit alpha- and beta-hemolytic activity, for identification. The microflora in $S.$ $broughtonii$ was less variable than sediments, and restricted species were isolated. We identified 17 genera of 88 species and 16 genera of 64 species from the two bays, respectively. A major proportion was comprised of $Bacillus$ species, with the $Bacillus$ $cereus$ group being the most common species among the $Bacillus$ strains, while $Paenibacillus$, $Lynsilbacillus$, and $Vibrio$ species were the second most abundant species. At the genus level, there were no significant microbial differences between the two coastal regions. 64 species were isolated from rare site (Jinhae bay), but more species (88) with greater variety were isolated from the frequent site (Gangjin bay). Therefore, it was assumed that the cause of mass mortality lay in the difference in specie-level diversity, and conducting investigations on the diagnosis of pathogenic species by challenging tests using isolated unique species.

• The Korean Journal of Malacology
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• v.10 no.1
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• pp.55-63
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• 1994

피조개, Scapharca broughtonii의 개체크기(작은 개체: 1.0-1.3cm, 큰 개체:4-5 cm), 수온(10, 15및 2$0^{\circ}C$), 염분(7,13,19,26 및 32 $\textperthousand$)에 따른 일반적인 대사경향과, 수온 1$0^{\circ}C$와 2$0^{\circ}C$ 그리고 부니 농도 25, 50, 100, 200, 400 600, 800및 1000ppm에서 15일간 노출시키면서 사망률, 산소소비율, 여수율 및 배설률을 측정한 결과는 다음과 같다.1. 일반적으로 피조개의개체 크기는 작은 개체일수록, 그리고 수온이 높을수록 비체중 산소소비율, 비체중 여수율 및 비체중 배설률은 높게 나타났다. 그리고 염분을 제외하고는 산소 소비율과 여수율은 염분농도의 증가에 따라 다소 증가하는 유사한 경향을 보인 반면, 비체중 배설률은 염분농도가 낮아질수록 낮은 양상을 나타내었다. 2. 1$0^{\circ}C$의 경우 작은 개체에서 LC$_{50}$은 557.11 ppm, 큰 개체에서 856.03 ppm이었고, 20%C의 경우, 작은 개체에서의 LC$_{50}$은 274.55 ppm, 큰 개체에서 346.26 ppm이었으며 1$0^{\circ}C$에 비해 2$0^{\circ}C$에서 특히 1000 ppm이상의 농도에서 사망률이 현저히 증가함으로써 부니에 의한 영향은 크게 나타났다.3.에 비해 2$0^{\circ}C$의 고수온구에서 부니의 농도가 높을수록 폐사율은 높게 나타났으며, 1$0^{\circ}C$와 2$0^{\circ}C$의 두 수온구에서 산소소비율과 여수율에 대한 각 농도별 부니의 영향은 유사한 경향을 나타내었다. 특히, 2$0^{\circ}C$에서 사망률이 현저히 증가하기 시작하는 부니농도 100ppm이상에서 산소소비율의 감소가 크게 나타났다. 그리고 암모니아태질소 배설률은 부니농도의 증가에 따라 차츰 증가를 보인후 600ppm이후부터는 다시 감소하는 경향을 보였다.

• Journal of the Korean Society of Food Science and Nutrition
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• v.21 no.4
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• pp.436-442
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• 1992

The present study was designed to analyze the lipid and fatty acid compositions of ark shell, Anadara broughtonii. The crude lipid was extracted by Bligh and Dyer's method, and then fractionated by TLC and quantitatively analyzed by TLC scanner. Lipid extracted from ark shell was fractionated into neutral and polar lipid by column chromatography with silicic acid. The fatty acid composition of lipid fractions were determined by gas liquid chromatography. Total lipid content of ark shell was 0.83% base on wet weight. The content of unsaponifiable matter was 20.19%, and iodine value was 156.13. The main components of total lipids were triglyceride, diglyceride, hydrocarbon, and sterol ester. The fatty acid composition of total lipid chiefly consisted of $C_{17 : 0}$, $C_{16 : 0}$, $C_{18 : 1}$ and $CT_{16 : 1}$. The main fatty acids of neutral lipid were $C_{16 : 0}$, $C_{18 : 1}$, $C_{22 : 1}$, $C_{18 : 0}$ and $C_{16 : 1}$. The major fatty acids of polar lipid were $C_{16 : 0}$, $C_{18 : 2}$, $C_{20 : 5}$ and $C_{22 : 6}$. In total lipid fractionation, saturated acid contents were high in all (SA>MA＞ PA), in neutral lipid fractionation, menoenoic acid contents were high in all (MA > SA> PA), and in polar lipid fractionation, saturated acid con-tents were high in all (SA> PA> MA).

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 2002.05a
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• pp.286-287
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• 2002

• Proceedings of the Korean Aquaculture Society Conference
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• 2002.08a
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• pp.176-177
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• 2002