Analysis of factors contributing to invasion success of an invasive alien species of nutria, Myocastor coypus, in Japan

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07514
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Mie University
• Principal Investigator: Kawamura Kouichi 三重大学, 生物資源学研究科, 教授 (80372035)
• Co-Investigator(Kenkyū-buntansha): 宮崎 多惠子 三重大学, 生物資源学研究科, 准教授 (60346004) ; 小林 秀司 岡山理科大学, 理学部, 准教授 (50260154)
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 定着成功 / 感覚適応 / 創始者効果 / ゲノム解析 / 局地適応 / 侵略的外来種 / 遺伝的多様性 / 比較解剖

Outline of Final Research Achievements

Invasion success of a invasive alien species of nutria, Myocastor coypus, in Japan was analyzed in physiology, behavior and genetics, focusing on the characteristics of species as well as those of founder in invasion. Compared with other rodents, nutria was characterized by the sensual development of hearing and smelling, contrary to the sensual degeneration of vision. The sensual development of hearing corresponds to vocal communication in community, and the sensual degeneration and development of vision and smelling were considered to be related to the aquatic adaptation of nutria. Among Japanese populations of nutria, genetic difference was found in microsatellite DNA (neutral gene), while it was not observed in major histocompatibility complex (functional gene). This suggests the importance of functional genes and the role of stabilizing selection in invasion success.

Free Research Field

分子生態学

Academic Significance and Societal Importance of the Research Achievements

本研究によりヌートリアの水棲適応の実体が明らかにされると共に，分子遺伝学的に見て日本におけるヌートリアの定着成功は導入時の遺伝的多様性（特に機能的遺伝子）の高さが大きく関係している事が考えられた．また，ヌートリアは視覚が退化的であるのに対し聴覚・嗅覚は発達し，個体間での音声コミュニケーションを行うといった行動生態的特徴も明らかとなった．こうした知見は現在課題となっている本種の効率的駆除・防除技術の開発において大きく貢献することが期待される．