2014 Fiscal Year Final Research Report
Lowering trend in the age of seaward migration and its relationship to environmental and physiological factors in masu salmon Oncorhynchus masou
| Project/Area Number |
24580257
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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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| Research Field |
General fisheries
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| Research Institution | Miyagi University of Education |
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Principal Investigator |
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| Project Period (FY) |
2012-04-01 – 2015-03-31
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| Keywords | サクラマス / oncorhynchus masou / 広瀬川 / 回遊 / 降河行動 / スチールヘッドトラウト / マスノスケ / 行動 |
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| Outline of Final Research Achievements |
In Hirose River, major part of masu salmon Oncorhynchus masou showed seaward migration in under yearling fall, which is 6 months earlier than the migrants inhabit in other rivers. Also, such under yearling migrants undertake half year migration in coastal area and show upstream migration in yearling spring. In order to reveal the mechanism modulating such migratory pattern, we investigated the effects of water temperature changes on swimming behavior of under yearling steelhead trout. As a result, we found that steelhead juveniles avoid high water temperature zone. Hence, it appears that increase of water temperature influences habitat choice and migratory patterns. We also found that under yearling Chinook salmon which stayed in upper and lower column of an aquarium showed downstream migratory behavior during under yearling fall and yearling spring, respectively. Such phenomenon implied that we can enhance migration during under yearling stage by modulating rearing conditions.
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| Free Research Field |
魚類行動生理学
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