• Journal of fish pathology
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• v.26 no.3
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• pp.193-206
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• 2013

The ark shell, Scapharca broughtonii is a marine bivalve mollusks belonging to the family Arcidae and important seafood for Korean and Japanese, and southern coast is brisk bays for the ark shell aquaculture. However, productivity of ark shell from these regions were rapidly reduced during the last decade due to mass mortality. The reason of this great damage has not yet been identified. To overcome this economic loss, diverse investigations were focused on environmental factors that affects in the physiology of S. broughtonii, but microbiological researches were performed insufficiently. Hemoglobin is one of the major blood component of ark shell and is damaged by some species of bacterial toxins. We concentrated on this red pigment because hemolysis could be the cause of ark shell mortality. In this study, we analyzed microbial diversity of underwater sediments in coastal regions and also existences in the body of S. broughtonii. We investigate about 4,200 isolates collected from June to September for microbial diversity of sediments and ark shell. We screened all of culturable microorganisms, and identified 25 genera 118 species, 24 genera 89 species, 30 genera 109 species and 39 genera 141 species, and selected 140 unique colonies for identification and challenge assay.

• Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.331-338
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• 2009

This study presents physiological rates of respiration and excretion, clearance rate, and assimilation efficiency of the ark shell Scapharca broughtonii, determined during 2007 from specimens collected in Gamak Bay on the south coast of Korea. Physiological parameters were measured monthly under static, laboratory controlled conditions with ambient conditions, and measurements were performed seasonally in order to estimate scope for growth and its probable sources of variation. Temperature directly influenced respiration and excretion. Clearance rates showed a tendency to be low during May-August, which is a period of gametogenesis. Assimilation efficiency was not significantly different seasonally and was independent of the concentration of chlorophyll a. The scope for growth was negative during high-temperature months (July-August), reflecting the high temperature and low clearance rate, and had its highest positive values during spring and autumn. The energy budget or growth potential of bivalves has been applied to other economically important species. Data on the physiological parameters and scope for growth of S. broughtonii obtained in this study will be used to assess the carrying capacity for ark shell cultivation.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.3
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• pp.342-350
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• 2020

The objective of this study was to investigate the sensory and nutritional characteristics of seasoned broughton's ribbed ark Scapharca broughtonii product (S-BRA). Based on 100 g, the proximate composition of S-BRA was 68.9 g moisture, 16.1 g crude protein, 4.0 g crude lipid and 4.0 g ash. The salinity was 2.2 g. Based on the results of a taste-intensity test using an electronic tongue, S-BRA had a stronger umami taste and less sourness than the control (BRA prepared with commercial seasoning sauce) (P<0.05). In a sensory evaluation, S-BRA scored higher for appearance, taste, flavor, and texture compared to the control. The total amino acid content based on 100 g of S-BRA was 16.04 g, and the major amino acids were aspartic acid, glutamic acid, leucine, and arginine. The S-BRA was higher in calcium, phosphorus, potassium, iron, and zinc than the control. The fatty acid content based on 100 g of S-BRA was 3,242 mg, and the major fatty acids were 16:0, 20:5n-3 and 22:6n-3. These results indicated that S-BRA had greater nutritional value than the control.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1435-1443
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• 2016

This study evaluated the sanitary state of seawater and shellfish in Yeoja bay from January 2014 to June 2016. The sampling stations for sanitary survey in Yeoja Bay was composed of 50 stations for seawater and 4 stations for ark shell and the samples have been collected monthly at a stated date. The total and fecal coliforms in seawater and Escherichia coli (E. coli) in shellfish were investigated as sanitary indicator bacteria, respectively. The geometric mean and the estimated 90th percentile ranges of total and fecal coliforms for seawater were <1.8-3.9, <1.8-2.6 and <1.8-29.7, <1.8-9.3 MPN/100 mL, respectively. The range of E. coli levels for ark shell were <20~330 MPN/100 g. The sanitary state in Yeoja bay was evaluated clean area according Korea criteria and conditionally approved area according US criteria and Class B area according EU criteria.

• Journal of Life Science
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• v.15 no.6 s.73
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• pp.879-883
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• 2005

This study was differentiated between Korea and China arkshells using PCR-aided RFLP method which could identify the variation for inter-and intra-species of arkshell (Scapharca broughtonii Schrenck) at the level of DNA. The DNA fragment patterns were compared after digesting gene of mitochondrial 16S rDNA with 8 kinds of restriction enzymes. A 720 bp DNA fragment corresponding to 16S rDNA gene was amplified by PCR with primers ArkF-3 and ArkR-3. PCR products were cut by restriction enzymes (Pvull, BamHI, Hinfl, HaeIII, EcoRI, RsaI, Ksp221, and BstX21), and RFLP pattern was studied. A unique 275 bp DNA band was observed in the samples from Dukyang, Gamak, Namhae, Jinhae, and Taean in Korea when treated by Hinfl, but Chinese arkshell did not show. Treatment of HaeIII could discriminate the sample of Namhae and Jinhae from Dukyang/Gamak/Taean, as well as Korean and Chinese arkshell based on a 700 bp. However, PuvII, BamHI, EcoRI, RsaI, Ksp221, and BstX21 showed the same of 700 bp band in Korean and Chinese arkshell. The phylogenetic tree inferred from PCR-RFLP pattern comparsion in Korean arkshell was different that the distance between Dukyang/Gamak/Taean and Namhae/Jinhae was approximately 7. In particular, the distance between Korean and Chinese arkshell was 25. Consequently, HinfI and HaeIII played an important role in a reliable molecular tool for rapid discriminating Korean and Chinese arkshell, as well as a intra-species in Korea.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.869-879
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• 2021

Methods for the development of home meal replacement seafood tailored to consumer needs for the advanced use of Broughton's ribbed ark Scapharca broughtonii (BRA) in Korea are required. In this study, we developed a cheese-topped, semi-dried, and seasoned Broughton's ribbed ark (S-BRA) tailored for the younger generation with an improved texture and fish odor. The optimization of conditions to improve the texture and fish odor was performed using RSM. The design of the model was appropriate because there was no significant difference (P>0.05) between the predicted and actual values of moisture content, hardness, and overall acceptance, and the optimal preparation conditions were a vinegar content of 2.68%, a soaking time of 62 min, a drying temperature of 60℃, and a time of 162 min. The S-BRA manufactured under these optimal conditions exhibited a lower odor intensity compared to the unsoaked and undried control, suggesting that the fish odor of S-BRA has been improved. The moisture content related to the texture of the S-BRA was lower than that of the control, and the hardness was higher. Therefore, the S-BRA developed in this study will appeal to people of all ages, especially the younger generation; their consumption is expected to increase.

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2006.05a
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• pp.264-266
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• 2006

• Korean Journal of Fisheries and Aquatic Sciences
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• v.53 no.3
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• pp.334-341
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• 2020

This study was conducted to optimize the processing conditions of seasoned broughton's ribbed ark Scapharca broughtonii products (S-BRA-P) using response surface methodology (RSM). The concentrated oyster extract content (X₁, w/w), amino-based seasoning powder content (X₂, w/w), and enzyme-treated stevia content (X₃, w/w) were selected as independent variables, and amino nitrogen (Y₁) and overall acceptance in a sensory evaluation (Y₂) were selected as dependent variables. The optimal conditions of X₁, X₂, and X₃ were 97.5%, 20.0%, and 0.9%, respectively, and the predicted values of the multiple response optimal conditions were Y₁ (1,030 mg/100 g) and Y₂ (8.3). Under the optimum conditions, the experimental values of Y₁ and Y₂ were 1,034 ± 6.0 mg/100 g and 8.5 ± 0.4, respectively, which was no significant difference from the predicted values (P<0.05). In conclusion, the optimized models of X₁, X₂, and X₃ for the preparation of soy sauce-based sauce were suitably fitted. The optimum amount of seasoning sauce was 13% for the preparation of S-BRA-P. The S-BRA-P, which was prepared by adding the seasoning sauce and the other subsidiary material [finely chopped spring onion (3.8%) and cheongyang hot pepper (4.6%)], had a superior taste, color, and odor.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.6
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• pp.880-889
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• 2021

The home meal replacement (HMR) market has attracted significant attention due to COVID-19 pandemic and products that utilize the combination of different processed ingredients are now being developed. In this study, Broughton's ribbed ark Scapharca broughtonii was soaked in seasoned soy sauce with the incorporation of mustard leaf Brassica juncea (M-BRA), which is known to have a unique texture as well as excellent functional properties such as antioxidation, to develop a regional specialty product. The optimal conditions for manufacturing M-BRA from the seasoned soy sauce (the sauce to be added [X₁] and the soaking time [X₂]), were examined using response surface methodology (RSM) to analyze the significance of the salinity (Y₁), amino-N content (Y₂), and overall acceptance (Y₃). The coefficient of determination (R²) between X₁-X₂ and Y₁-Y₃ were close to 1, thereby confirming the suitability of the RSM model. The optimal conditions were seasoned soy sauce addition of 140% and soaking time of 156 min. The M-BRA manufactured under these conditions exhibited superior overall acceptance compared to seasoned commercial soy sauce, which was used as a control. We expect that the market for M-BRA manufactured by combining marine and agricultural materials will expand owing to superior overall acceptance compared with commercial products.

• Fisheries and Aquatic Sciences
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• v.9 no.4
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• pp.153-159
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• 2006

The ark shell (or 'blood clam') Scapharca broughtonii is a filter-feeding bivalve that has red blood and inhabits waters approximately 10m in depth off the southern coast of South Korea. This study was part of a larger research project investigating the causes of death and restoration of shellfish resources, which are important aquaculture products in South Korea. We examined physiological responses related to survival, respiration, excretion, and amino acid changes as a result of changes in salinity. The 9-day median lethal salinity ($LS_{50}$) was 16.5 psu with confidence limits of 14.9-18.1 psu. At $25^{\circ}C$, the oxygen consumption and ammonia-nitrogen excretion rates were increased with decreases in salinity. Although the osmolality of individuals was acclimated within 2 h at 26.4 psu and 12 h at 19.8 psu, it took more than 5 days at a salinity of 13.2 psu, whereas no individuals acclimated and all died at a salinity of 6.6 psu. Of the amino acids present in the blood, taurine and alanine increased in response to decreased salinity. Tissues of the gill and the mid-gut gland were affected by decreasing salinity. These data will provide important fundamental information for examining the causes of mass mortality of shellfish in the summer.