• 제목/요약/키워드: Manila

검색결과 232건 처리시간 0.048초

Influence of Water Temperature and Salinity on Sand Ejection of Manila Clam, Ruditapes philippinarum

  • 강경호;김재민;김영훈
    • 한국패류학회지
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    • 제21권1호
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    • pp.13-17
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    • 2005
  • In this study, the influence of water temperature and salinity on sand ejection of Manila clams, Ruditapes philippinarum, was investigated. The result showed that, under different water temperature, the highest quantity of sand ejection was at $20^{\circ}C$, the value of which was 0.091 g, while the smallest one was only 0.058 g at 0$^{\circ}C$. The highest releasing rate, 95.79%, could be seen in $20^{\circ}C$ group, while $0^{\circ}C$ group was the lowest one, 85.29%. Under different salinity, 30 psu group had the highest value, 0.057 g, and 0 psu (freshwater) group was the lowest one, only 0.026 g. At the same time, the highest releasing rate appeared at 25 psu, which was 90%. 0 psu group was the lowest one in releasing rate, 60.47%. According to these results, we recommend that the clams should be placed into the clear seawater with about 25 psu of salinity at near $20^{\circ}C$ to let the clams perform the self-depuration. Better quality of clams containing less impurity in the aquaculture and commerce could be obtained from this pre-treatment.

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Cadmium Accumulation and Elimination in the Tissues of the Manila Clam, Ruditapes philippinarum, after Sub-chronic Cadmium Exposure

  • Jang, Seok-Woo;Kim, Seong-Gil;Choi, Ok-In;Kim, Seong-Soo;Kang, Ju-Chan
    • Fisheries and Aquatic Sciences
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    • 제12권4호
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    • pp.324-330
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    • 2009
  • Cadmium (Cd) accumulation and elimination were assessed in the tissues of the clam R. philippinarum at four experimental concentrations (control, 10, 20, 100, and $200\;{\mu}g/L$) over an exposure period of 2 weeks and an elimination period of 1 week. Cd accumulated in the digestive gland, gill, and residual clam tissues, and accumulation increased with time of exposure and concentration (100 and $200\;{\mu}g/L$). After 2 weeks of Cd exposure, the order of Cd accumulation in tissues was gill > digestive gland > residual tissues. An inverse relationship was observed between concentration factor (CF) and exposure level, but the CF showed an increase with exposure time. During the depuration period, Cd concentrations in the digestive gland, gill, and residual tissues decreased immediately on the cessation of exposure, except in individuals at the $200\;{\mu}g/L$ concentration. The Cd elimination rate from tissues decreased in the order of digestive gland > gill > residual tissues during the depuration period.

Infection status of intestinal parasites in children living in residential institutions in Metro Manila, the Philippines

  • Baldo, Eleonor-T.;Belizario, Vicente-Y.;De Leon, Winifreda-U.;Kong, Hyun-Hee;Chung, Dong-Il
    • Parasites, Hosts and Diseases
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    • 제42권2호
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    • pp.67-70
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    • 2004
  • A small scale survey was performed to know the infection status of intestinal parasite in children of the residential institutions and street communities in Metro Manila, Philippines. A total of 284 stool samples from 11 institutions and 3 street communities was examined by the formalin-ether concentration method. The scotch tape anal swab was adapted to 121 children to investigate the infection status of Enterovius vermicularis. It was found out that 62.0% of the children examined were positive for one or more intestinal parasites. Multiple infections were observed in 34.2% of the children. Among 172 children who gave detail information, the prevalence for Ascaris lumbricoides, Trichuris trichiura, and hookworm was 36.0%, 44.8%, and 7.0% respectively. Of the children examined, 47.7% were found to be harboring parasitic protozoans such as Entamoeba histolytica, Giardia lamblia, and Blastocystis hominis. The most prevalent of these protozoans was B. hominis with an infection rate of 40.7%. The prevalence of these infections among children living in institutions was relatively high. More efforts should be made to implement anthelminthic programs including bi-annual follow-up treatments.

우리나라 갯벌 조간대 바지락 Ruditapes philippinarum의 지역별 중금속 농축 변화 (Spatial Variations of Heavy Metal Accumulation in Manila clam Ruditapes philippinarum from Some Selected Intertidal Flats of Korea)

  • 안인영;지정연;최희선;표세홍;박현;최진우
    • 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).