Japan Geoscience Union Meeting 2018

Presentation information

[EE] Evening Poster

B (Biogeosciences) » B-PT Paleontology

[B-PT04] Biomineralization and the Geochemistry of Proxies

Sun. May 20, 2018 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall7, Makuhari Messe)

convener:Takashi Toyofuku(Japan Agency for Marine-Earth Science and Technology (JAMSTEC)), Hiroshi Kitazato(Tokyo University of Marine Science and Technology (TUMSAT)), Jelle Bijma(アルフレッドウェゲナー極域海洋研究所, 共同), Kotaro Hirose(Faculty of Science & Engineering, Waseda University)

[BPT04-P06] Test density of Ammonia sp. under variable pH

*Takashi Toyofuku1, Yukiko Nagai3, Katsunori Kimoto1, Osamu Sasaki2 (1.Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2.Tohoku university, 3.YNU)

Keywords:foraminifera, calcification, computer tomography

Foraminifera is major calcium carbonate producer in the sea (Langer et al., 1992, 1997? Sciebel et al., 2002). Ocean acidification is a threat on the marine organisms. The influence of ocean acidification on the calcareous foraminifera is the interesting topic for marine science community. Here, we try to measure test density (i.e. CT value) of cultured benthic foraminifera by micro x-ray computer tomography (MXCT). The individuals are grown under different pH settings. The CT value shows relatively lesser variability among experimental settings. It is not statistically significant the chamber size variability nor its increase among variable pH setting, although we also compare the chamber volume and it's increase among the condition. Generally, the size of chamber is increasing with growth at any conditions. The second chamber is smaller than the initial chamber with all individuals. Even the size of chamber increasing with growth from second added chamber, somewhat smaller chamber are added at the beginning of new whole of spiral. When new whole is starting, the older chamber is occupy some part of new chamber even though the outline of the chamber smoothly connected from older one-earlier chamber. This point is different from previous study with planktonic species (Fig. 5 of Sasaki et al., 2016).