| Project/Area Number |
17K15303
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| Research Category |
Grant-in-Aid for Young Scientists (B)
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| Allocation Type | Multi-year Fund |
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| Research Field |
Aquatic bioproduction science
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| Research Institution | Nagasaki University |
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Principal Investigator |
TAKEUCHI Seiji 長崎大学, 水産・環境科学総合研究科(水産), 准教授 (50758844)
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| Project Period (FY) |
2017-04-01 – 2020-03-31
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| Project Status |
Completed (Fiscal Year 2019)
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| Budget Amount *help |
¥4,290,000 (Direct Cost: ¥3,300,000、Indirect Cost: ¥990,000)
Fiscal Year 2019: ¥1,170,000 (Direct Cost: ¥900,000、Indirect Cost: ¥270,000)
Fiscal Year 2018: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
Fiscal Year 2017: ¥1,560,000 (Direct Cost: ¥1,200,000、Indirect Cost: ¥360,000)
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| Keywords | アサリ / 稚貝 / 生息場環境 / 漁場管理 / 投石・覆砂 / 足糸 / 隠蔽色 |
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| Outline of Final Research Achievements |
A hypothesis that polymorphic shell coloration of juvenile Ruditapes philippinarum clams functions to enhance visual crypsis was examined with a combination of a field survey and laboratory experiments. The results indicate that shell coloration (brightness) is positively associated with background brightness and that prey items with comparatively light (dark) coloration on dark- (light-) colored substrate are consumed by visual predators more immediately and at a higher rate than in the color-matched combinations. In addition, field surveys to investigate the relationship among byssus production, shell size, and somatic condition of clams and a histological study for byssal glands of clams were conducted. The results show that byssus production probability decreases with increasing shell size and declining somatic condition and that the lack of byssus production is not caused by the loss of the byssal glands.
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| Academic Significance and Societal Importance of the Research Achievements |
本研究は、天然のアサリ個体群がしばしば高密度帯を形成する砂礫底が果たす「物理的安定化」以外の役割に着目し、本研究全体を通じて砂礫底がもつ新たな役割の一端を解明した。特に、アサリ貝殻色―底質色のマッチングによる被食率の低減（隠蔽効果）の存在を野外調査と室内実験の組合せにより実証し、現行の漁場管理方法で見落とされてきた“色に基づく”管理の可能性を見出すことができた点は学術的にも社会的にも意義がある。
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