2022 Fiscal Year Final Research Report
Pathogen identification and epidemiological investigation of an unknown diseases in hatchery-reared leptocephalus of Japanese eel
Project/Area Number |
20K06244
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Research Category |
Grant-in-Aid for Scientific Research (C)
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Allocation Type | Multi-year Fund |
Section | 一般 |
Review Section |
Basic Section 40040:Aquatic life science-related
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Research Institution | Nihon University Junior College (2022) Nihon University (2020) |
Principal Investigator |
NAMBA Aki 日本大学短期大学部, その他部局等, 助教 (20445737)
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Co-Investigator(Kenkyū-buntansha) |
間野 伸宏 日本大学, 生物資源科学部, 准教授 (10339286)
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Project Period (FY) |
2020-04-01 – 2023-03-31
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Keywords | ニホンウナギ / レプトセファルス / 人工種苗 / 原虫症 / Caecitellus属 / 完全養殖 |
Outline of Final Research Achievements |
In the present study, we determined the nucleotide sequence of the 28S rRNA region of protozoan pathogen (Caecitellus spp.) in leptocephalus that occurred at the artificial seedling research facility of Japanese eel, and showed that the pathogen can be classified into three species. Based on the obtained sequence information, furthermore, specific PCR and quantitative PCR (qPCR) methods for Caecitellus spp. were established. Epidemiological surveys using both established methods showed that the protozoan pathogen was abundantly distributed in the parent fish tanks and that its abundance could be greatly reduced by free-flowing during collecting eggs. We also showed that in vitro culture of protozoan pathogen can be achieved by using Vibrio isolate from the parent fish tank.
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Free Research Field |
魚病学、水族微生物学
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Academic Significance and Societal Importance of the Research Achievements |
本研究では、二ホンウナギレプトセファルスの生産過程において甚大な被害をもたらすCaecitellus属原虫の診断・検出系を確立した。また、海面に接する種苗施設は本原虫病の感染リスクがあることも示すことができた。本原虫は、特定の餌料細菌を加えることでin vitro培養が可能であり、今後、有効な消毒法や治療法の確立に繋げていくことが期待される。二ホンウナギの完全養殖の実用化は、まだ道半ばであり、本研究の成果は、魚病の発生リスクに備えた人工レプトセファルスの飼育施設や飼育技術開発に寄与し、ニホンウナギの完全養殖に関する研究活動の安定化をもたらすものである。
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