Studies on the energy acquisition by the deep-sea benthos using colloidal gold and radioisotopes.

小型底栖生物的摄食率是用放射性同位素作为示踪剂来测量的。然而，由于生物体直接使用示踪剂，这种方法有高估的倾向。在本研究中，我首先试图发展一种以胶体金为示踪剂测定小型底栖生物摄食率的新方法。然而，发现金不适合作为示踪剂，因为在能量扩散X射线分析（EDX）中难以区分金和锌。另一方面，用铁代替金作示踪剂，结果很好。胶体铁比金更具有优势，因为它可以准确地定量摄食率，而不是用透射电镜超薄切片观察的耗时方法，而是用配备扫描电镜的EDX更容易的方法。利用这种新方法，可以准确地测定大槌湾4种浅水线虫的摄食率。利用线虫呼吸速率和线虫季节消长的数据，还可以直接测定线虫群落的年生产量。一开始，我打算用这种新方法来测量深海小型底栖生物的摄食率。然而，由于开发新方法的延迟，我错过了将胶体铁应用于深海物种的新方法的机会，但我只是在白凤丸前往南极海洋的航行中使用胶体金。放射性分析是定量测定金的最灵敏方法。我想把这个方法应用到我在航行中获得的材料上。此外，我想投喂铁标记POC的深海动物原位载人潜水器。

The ingestion rate of meiobenthos has been measured using a radioisotope as a tracer. However, this methods tended to overstimate, bacause of the direct use of the tracer by the organisms. In the present study, I firstly intended to develop a new method to measure the ingestion rate of meiobenthos using colloidal gold as a tracer. However, gold was found to be not suitable as a tracer because it is difficult to distinguish gold from zinc in the energy diffusive X-ray analysis (EDX). Use of iron instead of gold as a tracer, on the other hand, gave excellent reslts. It was especially advantageous to use colloidal iron than gold, because ingestion rates could be quantified accurately not by the time consuming method that the observation fo ultra-thin sectinis using transmission electron microscope, but rather easier way that using EDX equipped with the scanning electron microscope. Using this new method, ingestion rates of four species of shallow water nematodes in Otsuchi Bay could be measured accurately. With data on respiration rates and seasonal fluctuation of nematode aseemblages, the yearly production of nematode communtity also could be measured directly. In the beginning, I intended to use the new method to measure the ingestion rates of deep-sea meiobenthos. However, dut to the delay in developing the new method, I missed the chance to apply the new method of using colloidal iron to the deep-sea species, but I simply used colloidal gold as a during the Hakuho Maru cruise to the Antarctic Ocean. The radiation analysis is the most sensitive to measure the gold quantitatively. I woul like to apply the method to the materials I obtained during the cruise. In addition, I would like to fed iron labeled POC to the deep-sea animals in situ using manned submersible.