• Proceedings of the Malacological Society of Korea Conference
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• 2002.11a
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• pp.13-13
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• 2002

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.4
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• pp.476-480
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• 1999

Experiments were carried out to evaluate the tolerance of trochophores for pearl oyster, Pinctada fucata martensii and Pacific oyster, Crassostrea gigas using different concentrations of cryoprotectants : dimethyl sulfoxide (DMSO), ethylene glycol, glycerol and 1,2-propanediol. Each cryoprotectant with different concentrations was exposed for 5, 10, 15 and 20 minutes of immersion time. Survival rates were increased with decreased concentrations of cryoprotectant and decreased immersion time, and these differed from types of cryoprotectant. Survival rates of Pacific oyster trochophores were higher in DMSO and ethylene glycol, while those of pearl oyster trochophores were higher in glycerol and 1,2-propanediol. In case of trochophores from Pacific oyster, when 0.2 M sucrose was added in each cryoprotectant the survival rates were increased significantly.

• Asian-Australasian Journal of Animal Sciences
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• v.26 no.7
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• pp.916-920
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• 2013

The triploid Pacific oyster, which is produced by mating tetraploid and diploid oysters, is favored by the aquaculture industry because of its better flavor and firmer texture, particularly during the summer. However, tetraploid oyster production is not feasible in all oysters; the development of tetraploid oysters is ongoing in some oyster species. Thus, a method for ploidy verification is necessary for this endeavor, in addition to ploidy verification in aquaculture farms and in the natural environment. In this study, a method for ploidy verification of triploid and diploid oysters was developed using multiplex polymerase chain reaction (PCR) panels containing primers for molecular microsatellite markers. Two microsatellite multiplex PCR panels consisting of three markers each were developed using previously developed microsatellite markers that were optimized for performance. Both panels were able to verify the ploidy levels of 30 triploid oysters with 100% accuracy, illustrating the utility of microsatellite markers as a tool for verifying the ploidy of individual oysters.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.6
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• pp.750-757
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• 2016

This study investigated the quality, sensory characteristics and commercial potential of a rice snack prepared with dried oyster. Mild and spicy versions of the snack were produced using an oil coating and a mixed seasoning powder coating, respectively. The approximate compositions of the mild snack and spicy snack were 5.13% and 4.78% moisture, 8.92% and 8.94% crude proteins, 17.58% and 20.35% crude lipids, 1.88% and 1.87% ash, and 2% and 1.8% salt, with water activity values of 0.20 and 0.18 and a pH of 6.11 and 6.10, respectively. The color of the mild snack was lighter with more yellow and less red compared with the spicy snack. Thiobarbituric acid levels increased slightly, and hardness decreased slightly during storage at $27{\pm}2^{\circ}C$. The sensory score of the spicy snack was slightly higher than that of the mild snack. These results suggest that the spicy snack might have more commercial potential than that of the mild snack according to its higher sensory test score.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.50 no.2
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• pp.120-129
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• 2017

This study assessed the safety of raw oysters Crassostrea gigas for consumption during processing in a processing plant. Bacterial contamination (e.g., viable cell counts, coliform groups, Escherichia. coli and pathogenic bacteria) and chemical contamination (e.g., heavy metals and shellfish toxins) were measured on raw oysters, a processing equipment, employees and work areas. No total mercury, lead, paralytic shellfish poison, diarrheic shellfish poison or norovirus was detected in any post-harvested oyster samples. However, the cadmium level ranged from 0.1-0.2 mg/kg. The viable cell count, E. coli and coliform group levels in post-harvested oysters ranged from 4.00-4.54 log CFU/g, ND-210 MPN/100 g and 110-410 MPN/100 g, respectively. The viable contaminating cell counts on employees, equipment and work areas were in the range of $0.90-3.46log\;CFU/100cm^2$. Airborne bacteria in the work areas ranged from 0.60 to 1.81 log CFU/plate/15 min. Thus, no significant health risks were detected in the processing plant.

• Environmental Analysis Health and Toxicology
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• v.25 no.2
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• pp.161-168
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• 2010

The observed the toxic effect of WSF (Water Soluble Fraction) on development time, development rate, attachment rate, survival rate and growth of the larva during the early stage of the Pacific oyster, Crassostrea gigas. The time required early juvenile from the fertilized eggs exposed to crude oil (WSF) was about 13 hours in control group. But that of the crude oil dose group takes 12 hours, with shorter compared to control group. Development and attachment rate of the oyster significantly higher in 0.4 and 0.8 mg/L WSF compared to control group (P<0.05) but significantly lower more than 1.6 mg/L WSF (P<0.05). Survival rate of the oyster larva significantly higher in 0.4 and 0.8 mg/L WSF compared to control group (P<0.05) but significantly lower more than 2.4 mg/L WSF (P<0.05). Survival rate of spot showed no significantly difference compared to control group (P>0.05). Shell growth of the oyster were significantly lower more than 1.6 mg/L WSF compared control group (P<0.05). The effect concentration of crude oil showed that more 0.4 mg/L in development and attachment rate and more 1.6 mg/L in growth. Also, chronic exposure of crude oil even effect also in low concentration.

• Development and Reproduction
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• v.17 no.4
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• pp.337-343
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• 2013

Post-thawed larval rearing in Pacific oyster Crassostrea gigas was performed to investigate the survival rate with time course in three kinds of larvae cryopreserved. The highest survival rate and larval activity index (LAI) of post-thawed larvae were obtained from the permeation in 0.2 M sucrose and 2.0 M ethylene glycol (EG) at $-1^{\circ}C/min$ in freezing speed showing the survival rates just after thawing of 63.8% in trochophore, 84.1% in D-shaped veliger and 56.3% in early umbo veliger. In post-thawed larval rearing with food supply, the larvae lasted their lives until 24 hours in trochophore, 75 hours in D-shaped veliger and 57 hours in early umbo veliger. The results suggested that each larval stage post-thawed revealed no more further development to subsequent respective stage.

• The Korean Journal of Malacology
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• v.27 no.3
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• pp.223-228
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• 2011

To understand the role of hemocytes in the shell repair process, a hole was drilled in the right valves of the Pacific oyster, Crassostrea gigas, and the repair process was observed. Histological observations suggested that the exterior surface of the shell was repaired by aggregated hemocytes. The nuclei of the hemocytes were cleary stained in the regenerated shell while appearing fragmented after calcification at the $7^{th}$ day. Globular calcium granules were genegenerated from the hemocytic monolyer after 6 days of incubation which were morphologically and chemically identical with those from prismatic shell. Our finding suggested that the repaired prismatic shell was composed by aggregated hemocytes and that their endogenous calcium component might support the nucleation of calcium biomineralization during shell repair.

• The Korean Journal of Malacology
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• v.27 no.1
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• pp.35-42
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• 2011

In order to understand effect of polycyclic aromatic hydrocarbon (PAH) on shell repair of the Pacific oyster, Crassostrea gigas, shell regeneration experiments were carried out using oysters drilled a hole on the right valve. The change of pH and hemocytic characteristics in both extrapallial fluid and hemolymph were observed during the shell repair. The thickness of mantle tissue was apparently decreased, while necrosis in epithelium and periostracal gland was increased in response to PAH exposure. Our finding suggested that PAH could adversely influence on shell repair.

• Journal of Energy Engineering
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• v.27 no.1
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• pp.59-64
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• 2018

In this paper, we investigated the alternative sources of limestone. Oyster shell waste originated from aquaculture that causes a major disposal landfill problem in coastal sectors in southeast Korea. Their inadequate disposal causes a significant environmental problems araised. Bio mineralization leads to the formation of oyster shells and consists $CaCO_3$ as a major phase with a small amount of organic matter. It is a good alternative material source instead of natural lime stone. The utilization of oyster shell waste for industrial applications instead of natural limestone is major advantage for conservation of natural limestone. The present work describes the limestone and oyster shells hydraulic activity and chemical composition and characteristics are most similar for utilization of oyster shell waste instead of natural limestone.