九种现代双壳类壳体物相组成的对比研究

利用X射线衍射分析技术,对黄东海常见的9种现代双壳类壳体进行了物相分析,结果表明这些双壳类壳体分别属于三种类型,即文石质壳、方解石质壳、文石+方解石混合质壳。其中,菲律宾蛤仔(Ruditapesphilippinarum)、中国蛤蜊(Mactrachinensis)、四角蛤蜊(Mactraveneriformis)、薄片镜蛤(Dosinialaminata)、毛蚶(Scapharcasubcrenata)属于文石质壳,长牡蛎(Crassostreagigas)、中国不等蛤(Anomiachinensis)、海湾扇贝(Argopectenirradieus)属于方解石质壳,紫贻贝(Mytilusedulis)属于文石+方解石质的混合质壳;双壳类壳体物相组成与其生活方式有着一定的联系,营底栖埋入式生活者趋于形成文石质壳,底栖固着生活方式者趋于形成方解石质壳或混合质壳;不同大小的菲律宾蛤仔(Ruditapesphilippinarum)的物相组成上几乎没有差别,表明其壳体物相组成不受生命效应的影响。

Comparison Study on the Shell Mineralogy of 9 Species of Modern Bivalves Living in Yellow Sea

9 popular species of modern bivalves living in Yellow Sea were selected for their shell mineral analyses. By means of X-ray powder diffraction method, the types of minerals in the shells were discerned and their components were calculated. The result shows that aragonite or calcite is the dominant mineral in the shells. According to the component of mineral, shells were divided into three sub-type, namely, aragonite shell, calcite shell and mixed shell with component of mineral by >98% aragonite, >90% calcite, 37% aragonite and 63% calcite, respectively. Species in Veneroida, Arcida had aragonite shell. Species in Pterioida had calcite shell. And species in Mytiloida had mixed shell. This research suggests that mineral component of bivalve shell closely relates to its living pattern. Bivalves that live in the sand sediments are apt to form aragonite shell. In contrast, bivalves that live by attaching themselves on the hard bottom are apt to form calcite shell or mixed shell. Furthermore, this research also suggests that at least in some species the shell size has no significant influence on the mineral component of the shell.