Link between light-triggered Mg-banding and chamber formation in the planktic foraminifera Neogloboquadrina dutertrei.
Link between light-triggered Mg-banding and chamber formation in the planktic foraminifera Neogloboquadrina dutertrei.
复制标题
DOI：
10.1038/ncomms15441
复制
发表时间：
2017-05-15
影响因子：
16.6
通讯作者：
Martin P
中科院分区：
文献类型：
--
作者：
Fehrenbacher JS;Russell AD;Davis CV;Gagnon AC;Spero HJ;Cliff JB;Zhu Z;Martin P
海水温度和南极有孔虫的平均Mg/Ca比值之间的关系已经建立，为重建过去的海洋温度提供了一个重要的工具。然而，许多物种显示交替的高和低镁带内的壳壁，不能单独用温度来解释。最近的实验表明，壳内镁的变化Orbulina universa，形成一个球形的终端壳，节奏的昼夜光/暗周期。镁异质性是否也昼夜节奏的物种更复杂的壳形态是未知的。在这里，我们表明，高镁/钙方解石形成在夜间培养标本的多室物种Neogloboquadrina dutertrei。结果表明，N. dutertrei在最终的室形成之后添加了大量的方解石和几乎所有的Mg带。这些结果对解释N. dutertrei和建议昼夜镁显带是一个内在的组成部分，生物矿化在南极有孔虫。昼夜光/暗周期的影响程度在有孔虫镁异质性与复杂的壳形态仍然未知。在这里，使用高度空间分辨的分析技术，作者调查镁带和钙化同位素标记Neogloboquadrina dutertrei标本。
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. The degree to which the diurnal light/dark cycle influences Mg-heterogeneity in foraminifera with complex shell morphologies remains unknown. Here, using highly spatially resolved analytical techniques, the authors investigate Mg-banding and calcification in isotope-labelled Neogloboquadrina dutertrei specimens.