• Environmental Analysis Health and Toxicology
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• 제25권4호
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• pp.287-294
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• 2010

Objectives : The aim of this study was to verify the intersexuality of Crassostrea gigas and Ruditapes philippinarum in southern coastal waters of Korea. Methods : Specimens of Crassostrea gigas (n=363) were collected from six areas of Tongyeong, Geoje and Yeosu. Ruditapes philippinarum (n=221) was collected from five areas of Yeosu. The sex ratio and intersexuality were determined after observing gonad preparations. Results : The rate of intersexuality in Crassostrea gigas was 16.25%, with females (24.79%; n=30/121) exhibiting a higher rate than males (11.98%; n=29/242). The rate of intersexuality in Ruditapes philippinarum was 24.43%, with females (37.76%; n=37/98) exhibiting a higher rate than males (13.82%; n=17/123). Conclusions : The results of this study suggest that intersexuality is induced by aquatic pollutants such as endocrine disrupting chemicals (EDCs).

• Ocean and Polar Research
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• 제28권3호
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• pp.215-224
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• 2006

Spatial variation of heavy metal accumulation was investigated in Manila clam Ruditapes philippinarum collected from several tidal flats. Sediment metal levels varied highly among the sites, which was attributed primarily to differences in Fe and organic carbon contents and in part to gain size. Significant differences in metal concentrations also were found in the clam tissue among the different sampling sites. However, except for a few metals (Mn, Zn, Pb), which showed some elevation, the variations in the clam tissue were not related to the variations in the sediment. This is likely because most metals in filter-feeding herbivores such as R. philippinarum accumulated as a result of feeding on suspended particles such as phytoplankton and organic detritus in the water column, not in bottom sediment. In addition, tissue weight for a specific shell size varied significantly among the sites, and increased tissue mass indicating a good nutritive condition likely caused a subsequent dilution of body metals leading to reduced weight-specific concentrations of some metals (Cd, Zn, Cu, Co).

• 한국양식학회:학술대회논문집
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• 한국양식학회 2004년도 수산관련학회 공동학술대회 발표요지집
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• pp.506-507
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• 2004

• 한국패류학회:학술대회논문집
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• 한국패류학회 2003년도 추계학술대회
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• pp.12-12
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• 2003

• 한국수산과학회지
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• 제34권3호
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• pp.190-193
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• 2001

바지락의 용존산소 농도에 따른 SFG (Scope for growth)의 변화를 알아보기 위하여 수온 $23\pm0.5^{\circ}C$와 일반해수에서 반수치사농도, 여수율, 호흡률, 암모니아 질소배설률 및 동화효율 등을 측정하였다. 바지락의 용존산소 농도의 감소에 따른 $LC_{50}$은 2.4mgDO$L^{-1}$였다. 여수율과 호흡률은 실험용액의 용존산소의 감소에 따라 대체로 감소하는 경향을 보인 반면, 암모니아 질소 배설률은 용존산소의 감소에 따라 증가하였다. 동화효율은 6.5mgDO $L^{-1}$에서는 $68.2\%$였으며, 3.5 mgDO $L^{-1}$ 이하의 농도에서는$29.8\~39.3\%$로 차이를 나타내지 않았다. 용존산소의 농도에 따른 SFG는 2.5mgDO $L^{-1}$ 이상에서는 양의 값을 나타내어 생존 및 성장이 가능한 것으로 나타났다.

• 한국패류학회지
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• 제28권1호
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• pp.29-35
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• 2012

Growth patterns of the Manila clam, Ruditapes philippinarum in each tidal level were studied in the intertidal zone in Tae-an on the west coast of South Korea from April to August 2009. Environmental factors and the specimens of R. philippinarum were monthly collected at three intertidal locations: low intertidal zone, low-middle intertidal zone and middle intertidal zone. Temperature of sediment in low intertidal zone were lower than those in other intertidal locations. Concentrations of Chl-${\alpha}$ were not significantly different between in each tidal level. Exposure hours in low intertidal zone were shorter than those in other intertidal locations. Density of each year class in low intertidal zone were higher than those in low-middle intertidal zone and middle intertidal zone. Growth factors of R. philippinarum in low intertidal zone were better than those in other intertidal locations. The growth rate of under one year class individuals of low intertidal zone were higher than those in low-middle intertidal zone and middle intertidal zone, before the main recruitment period of R. pilippinarum. Although the growth patterns of R. philippinarum may be affected by various environmental factors, we suggests that the exposure duration is the main affect in the growth patterns of R. philippinarum in intertidal zone.

• 한국수산과학회지
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• 제49권2호
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• pp.137-145
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• 2016

This study screened the biological activity of an acidified gill extract of the Manila clam Ruditapes philippinarum including antimicrobial, hemolytic, membrane permeabilization, and DNA-binding activity, and purified the antimicrobial material. The acidified gill extract showed potent antimicrobial activity against Bacillus subtilis and Escherichia coli without significant hemolytic activity, but showed no membrane permeabilization or DNA-binding ability. An antimicrobial material was purified from the acidified gill extract using C₁₈ reversed-phase and cation-exchange high-performance liquid chromatography (HPLC). Treatment of the purified material with trypsin completely abolished all of the antibacterial activity against Bacillus subtilis, suggesting that the purified material is a proteinaceous antibiotic. The molecular weight of the purified material was 2571.9 Da, but no primary structural information was obtained due to N-terminal blocking. A future study should confirm the primary structure. Our results suggest that the Manila clam gill contains proteinaceous antibiotics that have a role in first-line defense. This information could be used to better understand the Manila clam innate immune system.

• 한국수산과학회지
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• 제39권spc1호
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• pp.123-131
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• 2006

Immmune parameters of the Manila clam Ruditapes philippinarum collected from four tidal flats, Nudong, Gonam, Hwangdo and Bangpo on Anmyeon-do, Korea were optimized and evaluated at the single cell level using flow-cytometry Hemocytes were withdrawn from the sinus of each clam, and total hemocyte counts (THC), phagocytosis rate, hemocyte mortality (HM) and DNA damage of hemocyte were analyzed. The highest hemocyte counts was recorded from the clams collected from Gonam, followed by Hwangdo, Nudong and Bangpo (P<0.001). Phagocytosis rate and hemocyte mortality of Gonam and Nudong clams were significantly higher than those of clams from Hwangdo and Bangpo (P<0.001). DNA damage in the clams from Nudong was higher twice than that of clams from Gonam (P<0.05). We suggest that the flow-cytometry has a high potential for evaluation of immunity of marine bivalves.

• 한국수산과학회지
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• 제52권5호
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• pp.511-518
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• 2019

Evaluating the habitat suitability of potential aquaculture sites for cultured species is critical to the sustainable use of tidal flats. This study evaluated the habitat suitability index (HSI) of 12 sites in a tidal flat aquaculture farm at Geunso Bay, Taean, in June 2016. The parameters used to model the suitability index were Growth (water temperature, chlorophyll ${\alpha}$, hydrodynamics), Survival (sediment-sand, mean size, air exposure), and Environment (DO, salinity). The HSI was calculated using weighted and No weighted geometric means. The results showed high habitat suitability at the bay's entrance (HIS; No weighted, 0.60-0.70; weighted, 0.60). Hydrodynamics, air exposure, sediment-sand and mean size are thought to have a significant impact on habitat selection by Manila clams Ruditapes philippinarum. This study explored the optimum habitat for Manila clams by calculating the HSI, providing basic data for tidal flat management.

• 한국패류학회지
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• 제29권1호
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• pp.7-13
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• 2013

본 연구는 납에 노출된 바지락, Ruditapes philippinarum 의 생물학적 반응을 알아보고자 하였다. 실험기간은 4주였으며, 실험구는 대조구 1개와 납 노출구 3개 (0.25, 0.50 and 1.00 mg/l) 였다. 실험 결과 납은 바지락의 생존율과 산소 소비율의 저하 및 기관계의 조직학적 변성을 유도하는 것이 확인 되었다. 납 노출구에서 산소소비율은 25-72% 감소하였다. 기관계의 조직학적 분석 결과, 외투막 상피층과 결합조직층의 변성, 아가미 점액세포의 증가와 상피세포의 괴사, 발에서는 상피층의 붕괴, 점액세포의 감소 및 혈림프동의 확장과 결합조직층의 변성을 나타냈다. 소화맹낭의 소화선세관에서는 호염기성세포와 상피세포의 위축 및 농도 의존적으로 lipofuscin의 축적이 확인되었다.