2016 Fiscal Year Final Research Report
The spawning ecology of Japanese eels
| Project/Area Number |
26450268
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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 |
Aquatic bioproduction science
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| Research Institution | Kindai University (2016)
Nihon University (2014-2015) |
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Principal Investigator |
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| Project Period (FY) |
2014-04-01 – 2017-03-31
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| Keywords | ニホンウナギ / 卵 / 内部潮汐 / UNA-CAM / ポップアップタグ / 日周鉛直移動 / 光 / 水温 |
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| Outline of Final Research Achievements |
Our analysis of the oceanic migratory behavior of large female Anguilla japonica silver eels with pop-up satellite archival tags found that they first use the Kuroshio Current and then go south into the open sea near the Ogasawara Islands. The daily rhythm of diel vertical migration of Japanese eels observed in the open sea and their spawning area was the same behavior found in all areas during their spawning migration. A clear relationship between the upper and lower limits of migration and the sun and moon light and water temperature was found. Their experienced temperatures estimated from the development rate of collected eggs was not significantly different from the environmental temperature from CTD data, only if spawning occurred at 1:00 at night 3 days before new moon in all cases. Therefore, we hypothesize that Japanese eels spawn at about 1:00 a.m. and internal tide patterns may contribute to the mechanisms that determine the places they spawn in the open ocean.
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| Free Research Field |
魚類生態学
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