Palaebiological study of 'living fossils' (1991)

1. 安倍和冢越于7月访问了澳大利亚，出席了第11届介形虫国际研讨会并发表了论文。他们和斯旺森博士讨论了一种活的介形虫，马那瓦，斯旺森博士在新西兰附近发现了马那瓦的活标本。Abe研究了从古生代到近代的肌类介形类甲壳和附属物的功能形态。Tsukagoshi注意到一些足类介形虫柔软部位的分割，并从总体上研究了介形虫的进化。Hayami和Kase在琉球的几个海底洞穴中发现了丰富的软体动物组合，并对其形态和生态独特性进行了研究。该动物群包括“活化石”属、海藓属和碧齿蚌属，以及许多微小的软体动物，它们在属组合和发育策略上与深海动物群惊人地相似。Oji收集了骏河湾的活海百合，并对其进行了培养，获得了许多关于其生态，功能形态和自主后手臂再生的信息。吉田考察了南太平洋地区的板块构造，为研究当今活化石的分布模式是如何经过一个地质时代形成的过程提供了基础知识。Abe利用VTR对介形类动物的交配行为进行了研究，发现附属物的形态特征在该物种的早熟或求偶行为中得到了更好的描述。类似的方法将应用于Manawa，以了解介形类动物交配行为的进化。——获得了关于南太平洋地区“活化石”的各种重要而有用的知识。分子生物学方面将在以后进行研究，以阐明这些活化石如何以及为什么在漫长的地质时间内保持其形态不变的过程。

1. Abe and Tsukagoshi visited Australia in July to attend and preset papers at the 11th International Symposium on Ostracods. And they discussed on a living ostracod, Manawa with Dr. Swanson who have discovered living specimens of Manawa from off Newzealand. Abe investigated functional morphology of the carapace and appendages of myodoeopid ostracods through the time from Palaeozoic to Recent. Tsukagoshi noticed the segmentation in the soft parts of some podoeopid ostracods, and studied the evolution of ostracods in general.2. Hayami and Kase found a rich molluscan assemblage in several submarine caves in Ryukyu, and its morphological and ecological uniqueness was examined. This fauna contains 'living fossil' genera, Neritopsis and Pycnodonte, and numerous minute molluscs which are surprisingly similar to deep-sea fauna in generic assemblage and developmental strategy.3. Oji collected living crinoids from Suruga Bay and cultured them, obtaining much information about their ecology, functional morphology and regeneration of arms after the autotomy.4. Yoshida examined plate tectonics in the South Pacific region, providing a basic knowledge to investigate the process how the present-day distribution patterns of the living fossils were made through a geologic time.5. Abe studied mating behaviour of ostracods using VTR, and found that the morphological features of appendages are better described in the context of premating or courtship behaviour of the species. Similar approach will be applied to Manawa to understand the evolution of mating behaviour of ostracods.--- Various important and useful knowledge has been obtained about 'living fossils' in the South Pacific region. Molecular biological aspects will be examined hereafter, to clarify the process how and why these living fossils have kept their morphology unchanged through a long geological time.