Skip to main content
eScholarship
Open Access Publications from the University of California

Link between light-triggered Mg-banding and chamber formation in the planktic foraminifera Neogloboquadrina dutertrei.

  • Author(s): Fehrenbacher, Jennifer S
  • Russell, Ann D
  • Davis, Catherine V
  • Gagnon, Alexander C
  • Spero, Howard J
  • Cliff, John B
  • Zhu, Zihua
  • Martin, Pamela
  • et al.
Abstract

The relationship between seawater temperature and the average Mg/Ca ratios in planktic foraminifera is well established, providing an essential tool for reconstructing past ocean temperatures. However, many species display alternating high and low Mg-bands within their shell walls that cannot be explained by temperature alone. Recent experiments demonstrate that intrashell Mg variability in Orbulina universa, which forms a spherical terminal shell, is paced by the diurnal light/dark cycle. Whether Mg-heterogeneity is also diurnally paced in species with more complex shell morphologies is unknown. Here we show that high Mg/Ca-calcite forms at night in cultured specimens of the multi-chambered species Neogloboquadrina dutertrei. Our results demonstrate that N. dutertrei adds a significant amount of calcite, and nearly all Mg-bands, after the final chamber forms. These results have implications for interpreting patterns of calcification in N. dutertrei and suggest that diurnal Mg-banding is an intrinsic component of biomineralization in planktic foraminifera.

Many UC-authored scholarly publications are freely available on this site because of the UC's open access policies. Let us know how this access is important for you.

Main Content
Current View