Temperature dependence of aragonite and calcite skeleton formation by a scleractinian coral in low mMg/Ca seawater
Temperature dependence of aragonite and calcite skeleton formation by a scleractinian coral in low mMg/Ca seawater
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DOI：
10.1130/g39516.1
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发表时间：
2017-12-01
期刊：
影响因子：
5.8
通讯作者：
Yuyama, Ikuko
中科院分区：
文献类型：
--
作者：
Higuchi, Tomihiko;Shirai, Kotaro;Yuyama, Ikuko
温度依赖性的文石和方解石的形成石珊瑚进行了研究，在低摩尔（M）镁/钙海水，复制波动的mMg/Ca水平普遍在整个中生代Eon的实验条件。孵化和骨骼生长监测的青少年的石珊瑚Acropora solitaryensis为4个月的浮游阶段，在海水中的镁/钙比为5.2，1.0，和0.5，温度为19-28摄氏度，表明，多态性的现今的石珊瑚在低镁/钙海水也受到海水温度的影响。然而，珊瑚产生的文石比在相同条件下无机CaCO 3沉淀实验中形成的文石更多，除了在19摄氏度。虽然文石含量反映了后者的结果（非生物）实验在19摄氏度，它建议文石珊瑚控制骨骼形成生物低镁/钙条件下，在较高的温度下，生长速度更快，在25摄氏度和19摄氏度的所有镁/钙比例较慢。与现今海水中镁/钙水平为5.2时的生长速率相比，在镁/钙水平为1.0和0.5时，幼年生长分别下降了62.8% +/- 14.7%和56.7% +/- 6.7%;结果表明，文石珊瑚的生长在低镁/钙条件下的不同季节温度下受到抑制。这支持了以前的研究结果，从变温的角度来看，在低镁/钙（白垩纪）海水中，石珊瑚生长较慢，解释为一个可能的解释在白垩纪石珊瑚礁建设的间隙。
Temperature-dependent aragonite and calcite formation by scleractinian corals were examined in low molar (m) Mg/Ca seawater, the experimental conditions replicating the fluctuating mMg/Ca levels prevailing throughout the Phanerozoic Eon. Incubation and skeletal growth monitoring of juveniles of the scleractinian coral Acropora solitaryensis for 4 months from the planula stage, in seawater with mMg/Ca ratios of 5.2, 1.0, and 0.5, and temperatures of 19-28 degrees C, indicated that polymorphism of present-day scleractinian corals in low mMg/Ca seawater is also influenced by seawater temperature. However, corals produced more aragonite than formed in inorganic CaCO3 precipitation experiments under the same conditions, except at 19 degrees C. Although the aragonite content reflected the results of the latter (abiotic) experiments at 19 degrees C, it is suggested that aragonitic scleractinian corals controlled skeletal formation biologically under low mMg/Ca conditions at higher temperature, growth rates being faster at 25 degrees C and slower at 19 degrees C for all mMg/Ca ratios. Compared with growth rates under the present-day-equivalent seawater Mg/Ca level of 5.2, juvenile growth decreased by 62.8% +/- 14.7% and 56.7% +/- 6.7% under mMg/Ca levels of 1.0 and 0.5, respectively; the results suggest that growth of aragonitic scleractinian corals is suppressed throughout varying seasonal temperatures under low mMg/Ca conditions. This supports previous findings from variable temperature perspectives that scleractinian corals grow more slowly in low mMg/Ca (Cretaceous) seawater, interpreted as a possible explanation for the hiatus in scleractinian reef building in the Cretaceous Period.