Exploitation of niches and diversification of organisms by utilising invisible light: the new research field of photogeobiology

2017 Fiscal Year Final Research Report

• Project/Area Number: 16K13898
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Stratigraphy/Paleontology
• Research Institution: Osaka City University
• Principal Investigator: EZAKI Yoichi 大阪市立大学, 大学院理学研究科, 教授 (60221115)
• Co-Investigator(Kenkyū-buntansha): 品田 哲郎 大阪市立大学, 大学院理学研究科, 教授 (30271513) ; 後藤 慎介 大阪市立大学, 大学院理学研究科, 教授 (70347483)
• Research Collaborator: ADACHI Natsuko 大阪市立大学, 大学院理学研究科, 准教授 (40608759) ; TOKUDA Yuki 公立鳥取環境大学, 環境学部, 講師 (30779765) ; SENTOKU Asuka 琉球大学, 理学部, 助教 (00722802)
• Project Period (FY): 2016-04-01 – 2018-03-31
• Keywords: 紫外線 / サンゴ / ニッチ / 多様化

Outline of Final Research Achievements

Marine algae include many kinds of UV-absorbing compounds (mycosporine-like amino acids, MAAs), which occur in various proportions. Zooxanthellate dendrophylliid corals also contain MAAs, although with less variability in the proportions of different compounds than algae. In contrast, azooxanthellate dendrophylliids contain various types of photo-absorbing compounds that differ from MAAs. In addition, the zooxanthellate coral Oulastrea crispata possibly biosynthesises MAAs, and its black pigment in skeletons is derived from protoporphyrin. The organisms examined in this research take effective measures against UV irradiation, and instead of photosynthesis. They biosynthesise photo-related compounds in photoenvironments unique to the habitat conditions. The inclusion of protoporphyrin in skeletons indicates a defence mechanism against microbial impact in habitat niches. The results provide clues to the biochemical responses of organisms that aid in the exploitation of special niches.

Free Research Field

地球生物学