日本地球惑星科学連合2019年大会

講演情報

[E] ポスター発表

セッション記号 B (地球生命科学) » B-PT 古生物学・古生態学

[B-PT04] Biomineralization and the Geochemistry of Proxies

2019年5月26日(日) 17:15 〜 18:30 ポスター会場 (幕張メッセ国際展示場 8ホール)

コンビーナ:豊福 高志(国立研究開発法人海洋研究開発機構)、北里 洋(国立大学法人東京海洋大学)、Bijma Jelle(アルフレッドウェゲナー極域海洋研究所)、廣瀬 孝太郎(早稲田大学  大学院創造理工学研究科 地球・環境資源理工学専攻)

[BPT04-P07] Estimation of foraminiferal calcification process from live imaging and FIB-SEM approach

*豊福 高志1,2長井 裕季子1,3 (1.国立研究開発法人海洋研究開発機構、2.東京海洋大学、3.国立科学博物館)

キーワード:石灰化、有孔虫、イメージング

Calcareous foraminifera have been thought a major carbonate producer in ocean. Their tests (shells) are fundamental tools as paleo-environmental indicators in various studies because their calcareous tests have been archived as numerous fossils in sediment for geologic time and various environmental information are brought by faunal structure, shell morphology and geochemical compsitions of calccitic test. The other hand, the calcification process itself is interested for us. Pseudopodia sticking out into sea water build organic templates in the form of chamber. Calcium carbonate is precipitated on the both side of template within several hours. Calcium and carbonate are fixed at there by foraminiferal biological process. The newly added chamber wall was flexible in a first day, the chamber solidified in a few days and became a solid test. It is very interesting to record this process in video. Our studies showed the variable change of pH and Ca during the biomineralization of foraminifera by the application of fluorescent indicators (e.g. Toyofuku et al., 2017). Recently, we also apply the method to clear cut the site of calcification under SEM by focused ion beam (FIB-SEM)(Nagai et al., 2018). The nano-scale fine structures have been revealed the distribution of soft orgnic structures (i.e. pseudopodia) and hard tissue (precipitated calium carbonate)by this observation.