Evolutionary effects of interspecific variation in female mating frequency on male mating strategy

2019 Fiscal Year Final Research Report

• Project/Area Number: 17K07577
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Ecology/Environment
• Research Institution: Nagasaki Institute of Applied Science
• Principal Investigator: SHIGEMIYA Yusuke 長崎総合科学大学, 総合情報学部, 准教授 (00399213)
• Project Period (FY): 2017-04-01 – 2020-03-31
• Keywords: 交尾器破壊 / ゴミグモ / フェロモン / 求愛歌 / レーザードップラー振動計 / オス間闘争 / メスによる選択

Outline of Final Research Achievements

In Cyclosa octotuberculata which females are potentially able to copulate multiply, males did not choice females based on copulation background. On the other hand, in C. confusa which females are prevented from multiple copulation due to female genital mutilation, males choice virgin females in spring generation. Vibration signal (mating song) generated by males differed between species, but no evidence was found of males evolving their behavior to seize the opportunity for a single mating of C. confusa female. Two males entering a female's web did not seem to interfere with each other, and the female copulated with both males, suggesting females didn't choice males.

Free Research Field

動物生態学

Academic Significance and Societal Importance of the Research Achievements

メスの交尾器が破壊されることによる交尾回数の制限が、オスにどのような繁殖戦略を進化させているか検証した結果、1回交尾の種のオスは未交尾のメスを判別する能力があるものの、オス間闘争や求愛行動で有利となる進化は観察されず、1回しか交尾できないメスがオスを選択することなく配偶を行っていることが示唆された。メスの交尾器破壊という極端な父性確保が起こる種において、オスの繁殖成功がメスへの到着順序で決まることを示唆する結果は、動物の性選択のパターンとして特異な例と考えられる。