Elucidation of metapopulation structure of the endangered fish Ryukyu-ayu for planning its conservation

2017 Fiscal Year Final Research Report

• Project/Area Number: 15K07538
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Aquatic bioproduction science
• Research Institution: Research Institute for Humanity and Nature
• Principal Investigator: TAKESHIMA Hirohiko 総合地球環境学研究所, 研究部, 外来研究員 (50573086)
• Co-Investigator(Kenkyū-buntansha): 安房田 智司 大阪市立大学, 大学院理学研究科, 准教授 (60569002) ; 井口 恵一朗 長崎大学, 水産・環境科学総合研究科(環境), 教授 (00371865)
• Project Period (FY): 2015-04-01 – 2018-03-31
• Keywords: 生物多様性 / 絶滅危惧種 / リュウキュウアユ / DNA分析 / マイクロサテライトDNA / メタ個体群 / 河川環境 / 保全

Outline of Final Research Achievements

A good understanding the metapopulation structure of an endangered species can provide essential insight for planning its conservation. The fish Ryukyu-ayu consists of endangered populations on the island of Amami Oshima. To examine the metapopulation structure of this fish, we conducted ecological survey and genetic analysis. Generally, a metapopulation consists of a source population and surrounding sink populations. Our logistic regression analysis clearly showed that the small river with low flow rate is the sink river. It was also indicated that when the relatively large river with high flow rate was distant from the source river, the river was difficult to maintain population size. A total of 1235 individuals were collected from the island in 1992-2017 and genotyped using 38 microsatellite DNA markers. We detected subtle but significant differentiation among populations of the eastern populations on the island, although the western populations were genetically homogeneous.

Free Research Field

分子生態学