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

• The Korean Journal of Malacology
• /
• v.28 no.1
• /
• pp.73-79
• /
• 2012

Seasonal changes in biochemical composition of muscle, gonad-viceral, mass and whole body of the cultured ark shell, Scapharca broughtonii in the Gamag bay of Yeosu city were studied from December 2008 to November 2009 in relation to environmental condition and reproductive cycles. Average monthly water temperature in the winter was in the range of $7-12^{\circ}C$ and $20-25^{\circ}C$ in the summer, while the salinity fluctuated in the range of 30.1%-33.8‰ on the average. Seasonal fluctuation of the concentration of nutrient salt was the highest in September ($13.04{\mu}g/L$) with average annual concentration of $4.6{\mu}g/L$. The main spawning season of the ark shell was during the months of July and August, and the gonads were in inactive stage during the winter. The gonad-visceral mass contained lower amounts of proteins than the other body parts. The most marked changes in body composition were lipids and carbohydrates within the gonad-visceral mass, and protein for each of the organs was relatively consistent throughout the year. All the parts in the visceral sac displayed the highest changes during the gametogenic cycle while the contents of moisture and lipid within the visceral act displayed somewhat inverse relations with each other. Moisture content was the lowest during the inactive stage during which the lipid content is the highest. The lipid content was the lowest immediately following spawning with increase in the moisture content as the lipid is being consumed. Protein mass within the visceral sac was low in comparison to the muscle mass. It is deemed that carbohydrates, lipids and proteins in the visceral sac play the major role as the source of energy during the development process of the gonads, and used for maintenance of base metabolism when available food is scarce.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.55 no.6
• /
• pp.827-835
• /
• 2022

Commercial boiled frozen ark shell Scapharca subcrenata (BFAS) is generally used as a seasoned seafood products. One problem facing the industry is that quality decreases during thawing. This study investigated ways to improve quality and shelf-stability of BFAS for use as a non-thermally prepared seasoned seafood products. The Viable bacteria were detected in BFAS after thawing under running water, but were not detected after blanching for over 2 min at 95±5℃. Blanching and dewatering times were optimized by response surface methodology (RSM) to reduce the initial number of bacteria and improve BFAS texture. Experimental design was deemed appropriate because no significant difference (P>0.05) was observed between predicted and actual moisture content, hardness, and overall acceptance values. Optimal blanching and dewatering times were 210 s and 80 s, respectively. Optimized blanching and dewatering processes can significantly improve safety and BAFS qualities including texture. These results indicate that BFAS demand as a staple for home meal replacements can be increased by application of optimized blanching and dewatering processes, especially in Korean seafood processing companies where running water thawing is common.

• The Korean Journal of Malacology
• /
• v.30 no.1
• /
• pp.17-23
• /
• 2014

Ark shell Scapharca broughtonii length and total weight growth by density, which was hanging-cultured near the sea area of Yeosu-city, Hoenggan-island (below is Yeosu), showed inverse correlation with density. As for the average growth of shell length by density, the test area of 10 shells showed the best result as 5.21 mm, and it became lower as density became higher. Also, the increase of total weight by density showed the same result, thus on the whole, the increase of average shell length and total weight of 10-20 shell test area showed the better result than the test area of 30-40 shells. In addition, even if the parashell's shell length by density and total weight growth in the sea area of Namhae-gun, Mijo-fishing port (below is Namhae) showed inverse correlation with density, it showed the slighter inverse correlation than the sea area of Yeosu. As for the average growth of shell length by density, the test area of 10 shells showed the best result as 4.55mm, but the average growth of shell length by density in the test area of 20-40 shells appeared to be similar as 3.11, 3.36 and 3.27 mm. On the other hand, as for the increase of total weight by density, the test area of 10-20 shells showed the more increase than the test area of 30-40 shells. In conclusion, it is guessed that the culture density of 20 shells/$0.12m^2$ (166 shells / $1m^2$) would be appropriate when hanging-culturing the shells. At the sea area of A, the survival rate of Scapharca broughtonii parashell was 68-87% by density respectively, and it showed the density-dependent result, while the survival rate of sea area of Namhae, where phytoplankton as prey is abundant, showed the much better result as 91-100%. It is guessed that this may be due to the fact that the quantity of phytoplankton in sea area of Yeosu is just 55.89% of sea area of Namhae. When hanging-culturing the shells, the water temperature by sea area ranged from 16.22 to $25.66^{\circ}C$, salinity 30.07-33.48, pH 8.10-8.45, and DO 4.49-9.65 mg/L.

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

• Journal of the Korean Home Economics Association
• /
• v.23 no.3
• /
• pp.75-84
• /
• 1985

This studies was conducted to elucidate the taste components of shellfishes, producted in Korea. Four kinds of shellfishes including sea mussel, short-necked clam, corb shell and ark ahell were selected according to the higher sales order and cheaper retail price at 50 fish markets in Seoul in August 1982. The results are : Palatable taste of shellfishes should be caused by nucleotide related products, organic acids and free amino acids. Thus taste components found in four shellfishes were succinic, fumaric, and lactic acids as organic acids, glycine, alanine and glutamic acid as free amino acids.

• KIEAE Journal
• /
• v.7 no.1
• /
• pp.33-40
• /
• 2007

0.4 Million tons of shell powder have been disused as waste in KOREA and caused severe environmental pollution though shell powder can be utilized in real life for many ways. It is impending problem to recycle shell powder as it requires high expense for burying and temporary outside heap and causes severe environmental pollution being a main factor of ocean waste. To suggest the basic data for development of eco-friendly and high-function Wall Coatings Thin Textured Finishes, a wall coating sample was applied to indoor walls of a mock-up and temperature and humidity were measured to assess the thermal performance of it, and a survey of preference for the color sense and feel of the materials with a movie of specimens. The results of the study are following; 1) High insulation performance is shown from the assessment result of the room polystyrene board adhered on the walls then high humidity controlling performance is shown from that of the room polystyrene board coated by shell powder. This point out that shell powder has superiority for humidity controlling. 2) The result of thermal and humidity assessment shows that shell powder makes up for thermal conduction of the polystyrene board and same result can be expected from the assessment with materials which has similar thermal characteristics with polystyrene.3) Ranking of preferred specimens is; 1st Case 13, 2nd Case 17, 3rd Case 16, and 4th Case 12. Preferred shell powder was the ark shell. Preferred powder for plaster was the powder mixed with that sifted by 0.8mm, 100mesh and 40mesh, and for spray was the fine powder mixed with that sifted by 100mesh and 40mesh.

• Korean Journal of Food Science and Technology
• /
• v.34 no.6
• /
• pp.1130-1133
• /
• 2002

Domoic acid, and amnesic shellfish poison, is a neurotoxin frequently found in shellfishes. Guidance level for the consumable shellfish has been established as $20\;{\mu}g$ domoic acid/g by Health and Welfare Canada and U.S. FDA. Domoic acid is produced by pennate diatom, a Nitzschia pungens f. multiseries ingested by the shellfish. Content of domoic acid in shellfish samples collected along the Korean shoreline from May to December of 1999 was analyzed. The collection included 1 Gastropoda (Murex shell) and 11 Bivalvias (oyster, little neck clam, orient hard clam, venus clam, surf clam, ark shell, hard-shelled mussel, pen shell, jack-knife clam, pink butterfly shell, and granulated ark shell). Samples were homogenized, extracted with 50% methanol, filtered, and analyzed by reversed-phase liquid chromatography at 242 nm with mobile phase consisting of 10% acetonitrile and 0.1% trifluoroacetic acid. Recovery of the HPLC analysis was 95.80% (${\pm}1.09$). All tested samples showed no domoic acid at the detection limit of 50 ng/g.

• Journal of Aquaculture
• /
• v.21 no.4
• /
• pp.252-258
• /
• 2008

Gonadal development and reproductive cycle of the ark shell Scarpharca subcrenata were investigated by histological observations. Samples were collected monthly from March 2007 to February 2008 in the Yeoja Bay, Yeosu, Jeollanam-do, Korea. S. subcrenata was dioecious. The gonads consist of a number of oogenic follicle and acinus. Monthly changes in the gonad index reached a maximum in June and a minimum in September. Monthly changes in the condition index reached a maximum in April and a minimum in September. The reproductive cycle of this species can be divided into five successive stages: early active stage (January to April), late active stage (March to June), ripe stage (May to August), spent stage (July to September) and recovery and resting stage (September to March). The main spawning of S. subcrenata occurred in July and August in Yeoja Bay. The sex ratio of female to male was not significantly different from 1:1.

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