Elucidation of potential extinction factors based on the genetic structure of local populations of Pungitius kaibarae

2020 Fiscal Year Final Research Report

• Project/Area Number: 18K05686
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 39060:Conservation of biological resources-related
• Research Institution: Shinshu University
• Principal Investigator: Takata Keisuke 信州大学, 理学部, 特任准教授 (90197096)
• Co-Investigator(Kenkyū-buntansha): 高橋 洋 国立研究開発法人水産研究・教育機構, 水産大学校, 准教授 (90399650)
• Project Period (FY): 2018-04-01 – 2021-03-31
• Keywords: Pungitius kaibarae / mtDNA / ddRAD-seq / COLONY / Sequoia / Ne / PVA

Outline of Final Research Achievements

Genetic and ecological elucidations were performed to formulate effective conservation measures on the Ibaratomiyo Omono-type (Pungitius kaibarae) endemic populations in Yamagata. RAD-seq family analysis, which gives effective population size, and the ecological information, such as longevity, clutch size etc. were enabled to perform the population viability analysis (PVA analysis) to estimate the extinction probability for the next 100 years. It was estimated there is no dispersal among the three populations in the most recent generations. Population viability analysis based on the ecological and the genetic information revealed the three populations are at high risk of extinction from 56% to 78% within the next 100 years. These suggest that habitat management and facility breeding based on risk dispersion is necessary.

Free Research Field

保全生態学

Academic Significance and Societal Importance of the Research Achievements

日本では、淡水魚類の多くは程度の差こそあれ絶滅危惧種に指定されている。本研究ではP. kaibarae種群に属するイバラトミヨ雄物型個体群を例に遺伝子解析を用いることにより、保全する際の基本情報である有効集団サイズを推定することができることを示した。これを基に個体群の絶滅確率を的確に予測することができるようになった。
これまで保全活動を行う際に、絶滅という最悪の状態がどの程度起こりうるかを客観的に示すことが難しかった。遺伝的集団構造の解明および生態学的データや環境変動データを用いた百年単位での絶滅確率の推定を組み合わせることにより、保全対象個体群の状況を客観的に示すことができるようになった。