Adaptive strategies of photosymbiotic planktonic fpraminifera to global warming

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K14896
• Research Category: Grant-in-Aid for Early-Career Scientists
• Allocation Type: Multi-year Fund
• Review Section: Basic Section 40030:Aquatic bioproduction science-related
• Research Institution: Chiba University
• Principal Investigator: TAKAGI Haruka 千葉大学, 大学院理学研究院, 助教 (10785281)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 浮遊性有孔虫 / 地球温暖化 / 環境適応 / 光共生 / 共生藻 / 飼育実験

Outline of Final Research Achievements

Photosymbiosis, in which photosynthetic algae are maintained within a host's cell and are nutritionally interdependent, is an important ecology in warm, oligotrophic waters, and understanding its response to environmental changes is important. In this study, I examined (1) temperature tolerance, (2) changes in photophysiology, and (3) changes in symbiotic algal composition in photosymbiotic planktonic foraminifera under high water temperatures. The results showed that a healthy symbiotic system can be maintained regardless of water temperature up to 32°C, and that the composition of symbiotic algae is not affected by temperature. On the other hand, when the symbiotic algae were kept in isolation, they stopped growing at 30°C, suggesting that the symbiotic state may serve as a shelter for the algae against environmental stress.

Free Research Field

プランクトン生態学

Academic Significance and Societal Importance of the Research Achievements

浮遊性有孔虫のような微小プランクトンは，海洋の低次生態系を支える重要な構成生物であり，そのバイオマスや群集組成の変化は，より高次の生態系へ影響を及ぼす．従って，本研究で明らかにした温暖化への応答は，将来的な温室地球における海洋生態系の状態を予測するためにも重要である．また，共生という生態は，地球生命史において生物の多様性を生む要因のひとつであることから，環境変動に対する共生系の応答を理解することは，過去の海洋環境変動と，それに応じた生物の進化過程を紐解く上でも重要である．