We report the electron microscopy-based analysis of the major lateral tooth of the limpet Colisella subrugosa during early and intermediate stages of development. We aimed to analyze the structural relationship among the needle-like crystals of the iron oxide goethite, the amorphous silica phase that forms the tooth base and occupy inter-crystalline spaces in the cusp, and the chitin fibers of the matrix. Goethite crystals followed the three dimensional organization pattern of the chitin fibers in the cusp. In the tooth base, spherical individual silica granules were found in regions where the chitin fibers cross. The spherical granules near the interface between the tooth base and the cusp (junction zone) formed an almost continuous medium that could easily be ultrathin-sectioned for further analysis. By contrast, the nearby silica-rich region localized on the other side of the junction zone contained needle-like goethite crystals immersed in the matrix and presented a conchoidal fracture. The chitin fibers from the silica granules of the tooth base were dotted or undulating in projection with a periodicity of about 6 nm when observed by high magnification transmission electron microscopy. Very thin goethite crystals were present in the base of the cusp near the junction zone surrounded by silica. On several occasions, crystals presented internal thin straight white lines parallel to the major axis, indicating a possible growth around fibers. We propose that silica and iron oxide phases mineralization may occur simultaneously at least for some period and that silica moderates the dimensions of the iron oxide crystals.

我们报告了对帽贝 Colisella subrugosa主要侧牙的基于电子显微镜的分析在发展的早期和中期阶段。我们旨在分析氧化铁针铁矿的针状晶体、形成牙基并占据牙尖晶间空间的无定形二氧化硅相以及基质的几丁质纤维之间的结构关系。针铁矿晶体遵循尖端几丁质纤维的三维组织模式。在牙基中，在几丁质纤维交叉的区域发现了球形的单个二氧化硅颗粒。靠近牙根和牙尖（连接区）界面的球形颗粒形成了一种几乎连续的介质，可以很容易地进行超薄切片以供进一步分析。相比之下，位于连接区另一侧的附近富含二氧化硅的区域包含浸入基质中的针状针铁矿晶体，并呈现贝壳状断裂。高倍透射电子显微镜观察，来自牙基二氧化硅颗粒的几丁质纤维呈点状或波浪状投影，周期性约6nm。非常薄的针铁矿晶体存在于被二氧化硅包围的交界区附近的尖端基部。有几次，晶体呈现出平行于长轴的内部细直线白线，表明可能在纤维周围生长。我们建议二氧化硅和氧化铁相矿化可能至少在一段时间内同时发生，并且二氧化硅调节氧化铁晶体的尺寸。高倍透射电子显微镜观察，来自牙基二氧化硅颗粒的几丁质纤维呈点状或波浪状投影，周期性约6nm。非常薄的针铁矿晶体存在于被二氧化硅包围的交界区附近的尖端基部。有几次，晶体呈现出平行于长轴的内部细直线白线，表明可能在纤维周围生长。我们建议二氧化硅和氧化铁相矿化可能至少在一段时间内同时发生，并且二氧化硅调节氧化铁晶体的尺寸。高倍透射电子显微镜观察，来自牙基二氧化硅颗粒的几丁质纤维呈点状或波浪状投影，周期性约6nm。非常薄的针铁矿晶体存在于被二氧化硅包围的交界区附近的尖端基部。有几次，晶体呈现出平行于长轴的内部细直线白线，表明可能在纤维周围生长。我们建议二氧化硅和氧化铁相矿化可能至少在一段时间内同时发生，并且二氧化硅调节氧化铁晶体的尺寸。非常薄的针铁矿晶体存在于被二氧化硅包围的交界区附近的尖端基部。有几次，晶体呈现出平行于长轴的内部细直线白线，表明可能在纤维周围生长。我们建议二氧化硅和氧化铁相矿化可能至少在一段时间内同时发生，并且二氧化硅调节氧化铁晶体的尺寸。非常薄的针铁矿晶体存在于被二氧化硅包围的交界区附近的尖端基部。有几次，晶体呈现出平行于长轴的内部细直线白线，表明可能在纤维周围生长。我们建议二氧化硅和氧化铁相矿化可能至少在一段时间内同时发生，并且二氧化硅调节氧化铁晶体的尺寸。