| Project/Area Number |
12660170
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General fisheries
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
IMAI Ichiro Kyoto University, Graduate School of Agriculture. Associate Professor, 農学研究科, 助教授 (80271013)
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| Co-Investigator(Kenkyū-buntansha) |
NAKAHARA Hiroyuki Kyoto University, Graduate School of Agriculture, Professor, 農学研究科, 教授 (80026567)
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| Project Period (FY) |
2000 – 2001
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| Project Status |
Completed (Fiscal Year 2001)
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| Budget Amount *help |
¥3,500,000 (Direct Cost: ¥3,500,000)
Fiscal Year 2001: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 2000: ¥2,700,000 (Direct Cost: ¥2,700,000)
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| Keywords | Dinoflagellates / Dinophysis fortii / Diarrhetic Shellfish Poisoning / Mixotrophy / Nanoplankton / Picoplankton / Okaidaic acid / ELISA |
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| Research Abstract |
Diarrhetic shellfish poisoning (DSP) is not only the problem of public health but also of bivalve aquaculture due to the ban of harvest. Currently, several species of the dinoflagellates belonging to the genus Dinophysis are known to be causative organisms of DSP. However, there have been some cases in which the bivalave toxicity increased in the absence of Dinophysis, or in which the bivalve toxicity did not increase during blooms of Dinophysis such as D. acuminata and D. fortii. The mechanisms of DSP occurrences have been therefore enigma. Recent studies have indicated the mixotrophy of Dinophysis spp. The present study is a trial of screening of small-sized phytoplankton that are foods of Dinophysis and possible origin of DSP toxins.
Water samples were collected from Mutsu Bay, Aomori Prefecture. Many strains of pico- and nano-phytoplankton were isolated by the extinction dilution method. These strain culures were examined whether toxic or not by Enzime Linked Immunosorbent Assay (ELISA) for DSP. As a result, four strains from 163 were DSP positive by ELISA, however, it is necessary to confirm their toxicity by using of LC-MS in the future.
The cell numbers of Dinophysis spp. were counted, and simultaneously DSP toxins were assayed in seawater in size fraction of<5 μm by ELISA method. The results obtained by ELISA method for the toxicity of the fraction of small-sized plankton in seawater coincided with the toxicity of scallops by the official mouse assay. The occurrences of D. acuminata and D. fortii did not well correlated to the toxicity of scallops. It is suggested that the direct monitorings of plankton fraction in seawater by ELISA method is an effective tool to predict the DSP toxin contamination in scallops of aquaculture in the coastal areas.
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