然而，很多海洋生物的骨骼由一种叫作霰石的碳酸钙矿物变体组成。

In many marine creatures, however, the skeleton is composed of a mineral variety of calcium carbonate called aragonite.

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珊瑚虫也将如此，特别是那些骨架由霰石(一种极不稳定的碳酸钙形式)组成的种类。

So will corals, especially those whose skeletons are composed of aragonite, a particularly unstable form of calcium carbonate.

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另外，实验还显示，碳酸钙眼睛允许石鳖在水中和空气中达到相同的视力，这可能有助于它们适应潮汐变化。

For another thing, the experiments suggest aragonite allows the chitons to see equally well in air or underwater, something that's probably useful as tides ebb around the mollusks.

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