Morphology of ostracode vestibulum as an indicator of marine environments

海洋介形类在环境研究中是有用的，因为许多物种的地理分布和水深分布受底层水温、氧气和盐度等水质量性质的限制。本研究对介形虫边缘甲壳上发育在复片和外片之间的前庭的形态进行了观察，并探讨了其形状在环境因素下的变化特征。这些样本取自日本列岛及其周边海域。我们的主要目标是：1)确定指示典型海洋环境的最有用的介形虫种和属；2)确定与海洋环境相对应的前庭形状的形态学特征；3)通过培养实验检验前庭形状和结构随环境条件变化的分化；4)将前庭形状特征应用于介形虫分类及其系统发育分析。利用前厅的这些研究，对Aurila、Xestoleberis、Spinileberis、Vargula、Cytheropteron、Krithe、Ishizakiella等介形类进行了古生物学分析。通过这项研究，确实找到了一种成功的培养介形类的方法，除了能够阐明该物种的生活史外，还可以获得实验标本。进一步利用这项技术可能会导致其他海洋物种的养殖。

Marine ostracodes are useful in environmental studies because many species have geographical and bathymetrical distributions limited by water mass properties such as bottom water temperature, oxygen and salinity. In this study, we inspect the morphology of vestibulum which develop between duplicature and outer lamella on marginal carapace of ostracodes, and investigate the character of their shape for environmental factors. The samples were chosen from seas off the Japanese Islands and surrounding areas.Our main goals are 1) to determine the most useful ostracode species and genera indicating typical marine environments, 2) to determine the morphological characters of vestibulum shape corresponding to the marine environments, 3) to test the differentiation of vestibulum shape and structure changing by the environmental condition through culture experiment, 4) to apply the characteristics of vestibulum shape to the ostracode taxonomy and their phylogenetical analysis.These studies on the vestibulum were used to paleobiological analysis several ostracoda taxa, Aurila, Xestoleberis, Spinileberis, Vargula, Cytheropteron, Krithe, Ishizakiella etc.Through this research, a successful method for cultivating ostracodes was indeed found and in addition to being able to elucidate the life history of the species, it became possible to secure specimens for experiments. Further utilization of this technique may lead to the cultivation of other marine species.