Development of the culture methods of marine ostracodes for the environmental indicator species and paleobiological research

点击翻译按钮获取中文摘要

Two kinds of culturing system were planned in order to obtain a continuous supply of experimental organisms for paleobiological research. Firstly, a mother culture system having a near natural marine environment was tried. This culture, system had multiple species living together. The second system involved culturing of single species isolated in small petri dishes within the incubator.In the mother culture system, a rocky shore environment was experimented, and microhabitat of ostracodes were observed. Contrary to the general belief that certain ostracodes species lives in the calcareaous algae, the present results show that different species have different habitats. Some species live on the leaves, some others live surrounding the root of the weeds whereas other species live in the sediments. However, there are certain problems related with this culture system. As the number of individuals in a species reduces during the experiment, frequent addition of individuals from the natural habitat is essential. If it is possible to maintain a healthy growing sea weeds in the culture system, the number of individuals can be kept constant. The possible other factors include ultraviolet irradation and fast circulation of sea water.In the monoculture system, the Sr/Ca and Mg/Ca ratios were analyzed for the species of Xestoleberis hanaii. The results show that Sr/Ca ratio is independent of sea water temperature, where as the Mg/Ca ratio is dependent on sea water temperature. Especially, the ontogenetical observation of the chemical parameters prove that Mg is concentrated in organic layer within the carapace. This indicates that Mg has an important role in calcification process of the carapace. In this system, the problem of bacteria can be reduced by replacing not only the sea water but also the petri dish itself. Further, the quantity of food should be very less for this system and hence easy to culture.