2010 Fiscal Year Final Research Report
Ecological and genetic study on Lethentron japonicum of which biomass is remarkably dicreasing
| Project/Area Number |
20580191
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General fisheries
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| Research Institution | Hokkaido University |
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Principal Investigator |
GOTOU Akira Hokkaido University, 北方生物圏フィールド科学センター, 教授 (30111165)
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| Co-Investigator(Kenkyū-buntansha) |
YAMAZAKI Yuji 富山大学, 大学院・理工学研究部, 准教授 (30332654)
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| Project Period (FY) |
2008 – 2010
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| Keywords | カワヤツメ / 遡河回遊性生活史 / 資源量減少 / ハビタット利用 / 産卵場選択 / 遺伝的多様性 / 環境保全型資源管理施策 |
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| Research Abstract |
To elucidate the cause and effect of highly decreased population size of the Arctic lamprey, Lethenteron japonicum in the stream life period, the ecological field research for larvae and upstream migrating adults, and population genetic analysis of the Ishikari River populations were carried out. As a result, it was made clear that both the soft mud quantity on the stream bed and the abundance of detritus originated from the litter of fallen leaves played an important role for high survival of lamprey larvae. In addition, it was found that the water depth was important for spawning success of upstream migrating lamprey adults. The results from microsatellite DNA analysis showed the genetic diversity of Ishikari River populations decreased in recent years. On the basis of these results, we proposed some improvement plans of stream environments to restore the population size of this lamprey species.
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