X射线断层扫描技术在鲤鱼耳石对环境响应研究中的应用初探

作为生命矿物文石和球文石的载体,鱼耳石(fish otoliths)记载了鱼体生长过程中大量的环境信息。近30年来,其研究取得了很多成果,但利用医学技术的研究尚未见报道。文中尝试应用医学X射线断层扫描技术(CT)对取自河北白洋淀和北京密云水库的野生鲤鱼耳石进行分析研究。结果表明:白洋淀鲤鱼的星耳石和微耳石CT值均大于密云水库鲤鱼耳石相应的CT值,与白洋淀水体中的重金属元素含量明显高于密云水库水体中的重金属含量存在较好的相关性;同一水域星耳石与微耳石的CT值也存在明显差异,分析认为这种差异可能与元素的亲和性及占位方式有关。

Tentative application of computed tomography to the study of carp otoliths and their responses to environmental variations

As the carrier of biomineral aragonite,fish otoliths memorize various messages of environment through the fish's life.In the past three decades,quite a few achievements have been made in the studies of fish otoliths,but no advances in researches using medical instruments have been reported.The authors tentatively apply X-ray computed tomography(CT)to the studies of the internal structure of wild carp otoliths,with the CT value determined by variations in the sample density and element composition.The wild carps were collected respectively from Baiyangdian Shallow Lake in Hebei province and Miyun Reservoir in Beijing metropolis,whose water environments are quite different.The former has suffered serious pollution and eutrophication whereas the latter has nearly experienced no pollution.The primary result indicates that difference exists in CT values of otoliths for the carps from the above-mentioned two waters.With studies in-depth,it is possible that X-ray computed tomography could be served as a useful tool in the study of fish otoliths,and the CT values can be taken as typomorphic parameters to distinguish the waters with different degree of pollution.