Evolutionary mechanisms of Mullerian mimicry in millipedes through speciation process

2018 Fiscal Year Final Research Report

• Project/Area Number: 16K07482
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Biodiversity/Systematics
• Research Institution: Kumamoto University
• Principal Investigator: Tanabe Tsutomu 熊本大学, 大学院先端科学研究部(理), 教授 (30372220)
• Research Collaborator: HONMA Atsushi ; MOCHIDA Koji ; SOTA Teiji ; MAREK Paul E. ; KUWAHARA Yasumasa
• Project Period (FY): 2016-04-01 – 2019-03-31
• Keywords: 擬態 / 警告色 / ヤスデ / ハエ

Outline of Final Research Achievements

A possible Mullerian mimicry ring for gray aposematic body color was found between two groups of milliepdes of the family Xysotdesmidae in Japan, the Parafontaria tonominea species complex and Riukiaria millipedes. Moreover, possible deviations from the gray mimicry ring to orange or intermediate color between gray and orange morphs were found for some species of the Parafontaria tonominea species complex. Analyses suggested that the gray morph has higher aposematic function than the orange or intermediate morphs, whereas the gray morph was highly attacked by parasitoid flies. The formation of the gray mimicry ring seems to be affected by the balance between the two selective pressures of opposite direction. Multiple speciation events occurred in the Parafontaria tonominea species complex due to divergence of body and genital sizes may promote this body color evolution.

Free Research Field

進化生態学

Academic Significance and Societal Importance of the Research Achievements

本研究は、今までほとんど解明されていなかった、ミュラー型擬態の形成条件の一つを示した点で注目される。ある体色への選択圧の方向が、捕食/寄生者により異なる場合、その兼ね合いにより、ミュラー型擬態環の成立が決まることを野外の生物で示唆すことができた。この成果は、警告色の擬態研究のみならず、体色の進化研究一般に対して、インパクトを持つものと期待される。