Serpulids are the only polychaetes in which all species secrete calcium carbonate tubes. Some serpulid lineages, such as species in the genus Spirobranchus, possess a second kind of hard-calcified part—the operculum. The tube and operculum microstructure and mineralogy are highly variable among serpulid species, but this type of information is still scarce for some species. Furthermore, comparing the microstructure and mineralogical composition of species from warm and temperate waters helps to determine which are more susceptible to the effects of climate change. Therefore, the aim of this study is to determine and describe the microstructure and mineralogical composition of the tubes and opercula of three Spirobranchus species from warm and temperate waters of the Mexican Pacific. The microstructures of the two hard structures were analyzed with a scanning microscope and complemented by X-ray computed nanotomography; the mineralogy was determined by X-ray diffractometry. The tubes of the three species had two layers—inner and outer—and five microstructures were found in the tubes. Numerous pores cover the operculum of all three species and have an irregularly oriented prismatic (IOP) structure. The tubes of the three species were bimineralic but had different percentages of calcite and aragonite, whereas the opercula were only composed of aragonite. Given the mineralogical characteristics of S. spinosus and because its distribution is only in temperate waters, we may conclude it could probably be the main species negatively affected according to the climate change scenarios predicted for the end of this century.

蛇科动物是唯一一种所有物种都分泌碳酸钙管的多毛类动物。一些蛇类谱系，例如螺鳃类物种，拥有第二种硬钙化部分——厣。蛇类物种的管和鳃盖微观结构和矿物学差异很大，但对于某些物种来说，此类信息仍然很少。此外，比较温暖和温带水域物种的微观结构和矿物成分有助于确定哪些物种更容易受到气候变化的影响。因此，本研究的目的是确定和描述来自墨西哥太平洋温暖和温带水域的三种螺鳃类物种的管和鳃盖的微观结构和矿物成分。使用扫描显微镜分析了两种硬结构的微观结构，并辅以 X 射线计算机纳米断层扫描；矿物学通过X射线衍射测定。这三个物种的管子有内层和外层两层，并且在管子中发现了五种微观结构。所有三个物种的鳃盖上都覆盖着许多孔隙，并具有不规则定向的棱柱（IOP）结构。这三个物种的管是双矿物的，但方解石和文石的比例不同，而鳃盖仅由文石组成。考虑到S. spinosus的矿物学特征，并且由于其分布仅在温带水域，我们可以得出结论，根据本世纪末预测的气候变化情景，它可能是受到负面影响的主要物种。