Increased acidification of aquatic habitats due to climate change is damaging mollusks. Non-destructive methods for analysis are necessary to study these endangered species. We analyzed five Unionidae gastropods using Raman spectroscopy. Shells were primarily composed of aragonite, a polymorph of calcium carbonate found in shell microstructure. Lattice mode Raman peaks from vaterite, a thought to be rare polymorph of calcium carbonate, were identified in each mollusk. Vaterite is present in mollusks at instances of shell damage and subsequent repair. We demonstrate that Raman spectroscopy is sensitive to vaterite, and it may not be as rare as previously thought. We also collected Raman spectra across the interior of Lampsillis fasciola. This data was analyzed through multivariate analysis, combining Principal Component Analysis with Linear Discriminant Analysis (PCA-LDA). Results of PCA-LDA correlate with growth of the mollusks, demonstrating that Raman spectroscopy combined with multivariate analysis could be used to monitor shell growth.

中文翻译：

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淡水软体动物成分、生长和损伤修复的无损拉曼光谱测定

由于气候变化，水生栖息地的酸化加剧正在破坏软体动物。非破坏性分析方法对于研究这些濒危物种是必要的。我们使用拉曼光谱分析了五种Unionidae腹足动物。贝壳主要由文石组成，这是一种在贝壳微观结构中发现的碳酸钙的多晶型物。在每个软体动物中都鉴定了球霰石的晶格模式拉曼峰，球霰石被认为是一种罕见的碳酸钙多晶型物。球霰石存在于贝壳损坏和随后修复的软体动物中。我们证明拉曼光谱对球霰石很敏感，它可能并不像以前认为的那样罕见。我们还收集了Lampsillis fasciola内部的拉曼光谱. 该数据通过多变量分析进行分析，将主成分分析与线性判别分析 (PCA-LDA) 相结合。PCA-LDA 的结果与软体动物的生长相关，表明拉曼光谱结合多变量分析可用于监测壳生长。