| Project/Area Number |
18K05783
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Multi-year Fund |
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| Section | 一般 |
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| Review Section |
Basic Section 40030:Aquatic bioproduction science-related
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| Research Institution | Mie University |
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Principal Investigator |
Yodo Taiga 三重大学, 生物資源学研究科, 准教授 (00378324)
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| Project Period (FY) |
2018-04-01 – 2021-03-31
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| Project Status |
Completed (Fiscal Year 2020)
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| Budget Amount *help |
¥4,420,000 (Direct Cost: ¥3,400,000、Indirect Cost: ¥1,020,000)
Fiscal Year 2020: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2019: ¥2,080,000 (Direct Cost: ¥1,600,000、Indirect Cost: ¥480,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
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| Keywords | コクチバス / 外来魚 / 環境DNA / 安定同位対比分析 / 河川 / 特定外来生物 / 環境DNA分析 / 採捕調査 / 胃内容物調査 / 安定同位体比分析 / 河川内分布 / 食性 / 繁殖 |
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| Outline of Final Research Achievements |
The objective of this study was to understand the ecology of smallmouth bass in rivers, for which ecological knowledge is lacking despite concerns about serious damage in river environments, and to develop an effective control method. The study was conducted in the Kumozu River in Mie Prefecture, where the species had just invaded, and the following results were obtained: (1) Environmental DNA was used to determine the overall extent of the invasion. (2) Stomach contents analysis and stable isotope analysis revealed that the diet of the bass changes from aquatic insects to fishes with growth, and that it is highly dependent on ayu.(3) The feeding habits of prey fish at the invaded site were compared with those at the uninvaded site, and it was found that, in addition to direct predation, the fishes were indirectly damaged by food competition and predator avoidance behavior.
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| Academic Significance and Societal Importance of the Research Achievements |
流水域に適応的であることから河川での影響が懸念されていたにもかかわらず，これまで河川における生態的知見に乏しかった特定外来生物コクチバスについて，実際に魚類，特にアユへの食害が示唆されたことは，学術的，社会的な意義が大きい。また，開放的環境である河川では駆除を行うために外来生物の侵入範囲の特定が重要であるが，環境DNAを用いることにより労力や時間をかけずにこれを把握する手法を開発し，その精度が高いことを明らかにした。コクチバスを種特異的に検出可能な環境DNA配列は今後広く活用されると思われる。
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