中文摘要：

鱼耳石主要成分是CaCO3，主要以文石（或霰石）形式存在，在过去四、五十年来在晶体结构研究方面取得了较多的成果。然而，不同水域鲤鱼耳石CaCO3晶体结构信息特征与环境响应研究却未见报道。本文对密云水库和白洋淀水域鲤鱼耳石X一粉晶衍射结果进行了研究，并分析了两地晶胞参数a0、b0、C0和单位晶胞体积的差异。结果显示，两地耳石样品均由霰石组成，分属三种不同结构：两种六方晶系P6s／mmc（no．194）结构和一种斜方晶系Pbnm（Pnmano．62）结构。属于六方晶系的耳石样品中，密云水库鲤鱼耳石样品晶胞参数值比白洋淀更接近于标准值，且a0相对大而C0相对小;密云水库鲤鱼耳石样品单位晶胞体积比白洋淀的大，且偏离标准样品晶胞体积程度明显比白洋淀小得多。而对于斜方晶系的耳石样品却没有明显的结论。结合成分分析结果，两地晶胞参数的差异很好地与微化学成分差异一致，表明鱼耳石的晶体结构信息对鱼生活的水体水质和水环境相当敏感。这一发现表明鱼耳石晶体结构信息可能成为水化学环境的重要标型。

英文摘要：

Otolith of fish is made of CaCO3, and its crystal form is aragonite or vaterite. In the past forty or fifty years, quite a few achievements have been made in the study of the CaCO3 crystal structures in the otoliths, but no advances in the researches on therelationships between the features of the crystal structures of the fish otoliths and their living environments have been reported in literature. In this paper, the characteristics of crystal structures of CaCO3 in otoliths of carps from two areas with extremely different water environments, i.e., the seriously polluted Baiyangdian shallow lake and the Miyun reservoir, were studied by means of X-ray diffraction analysis, and the basic cells and dimensions were analyzed. The experimental results indicate that all samples from the two sites are composed of vaterites, which can be divided into three different crystal structures, namely, two types of hexagonal cells with space group P63/mmc and one type of orthorhombic cell with space group Pbnm. For the vaterites with the hexagonal cell, the dimensions of samples from the Miyun reservoir are much nearer to the standards than those from the Baiyangdian shallow lake, and a0 of the former is relatively bigger than the latter, but things are opposite for co. Moreover, the cell volume of vaterite from the Miyun reservoir is bigger than that from the Baiyangdian shallow lake, and the former is nearer to the standards than the latter. There exist no distinct results for the vaterites with the orthorhombic cell. The results of microchemical characteristic composition analysis show that the differences in the dimensions of basic cells of vaterites from the two localities are consistent with those in the microchemical characteristic compositions of vaterites from these localities. Therefore, the information of the crystal structure of vaterite in otolith of carp seems sensitive to water quality and water environment, and this can be regarded as an important indicator to the pollution degree of the water.