Research of genetic resources in the coastal intertidal zone around Oshika Peninsula

阐明复杂环境区海岸潮间带物种组成的季节和年际分布和变化规律是海洋物种和海岸环境保护的重要科学课题之一。本研究以大鹿半岛为研究对象，调查了大鹿半岛3个地区的4个地点的物种分布。此外，在形态相似的物种间也发现了遗传差异，并且在两种常见的星星鱼（Asterinapectinifera和Asterinapectinifera）中也发现了遗传变异。结果表明，在大鹿半岛的3个地区的4个地点，观察到了多种多样的种。不同季节和不同年份的分布差异不大，但夏季两种星星鱼的数量明显多于冬季。各地区的种类组成相似，但在越田冈冈加拉地区，大鹿半岛南部的种类多于北方的种类。结果表明，大鹿半岛地区的物种组成可以作为环境变化的一个有价值的指标。多板目物种间存在明显的遗传分化，多角虫属物种间的颜色变异具有遗传一致性。两种星星鱼的遗传多样性均高于软体动物。同工酶标记被认为是用于检测物种和遗传特征如遗传变异性的可用遗传标记。我们将在2001年出版一本题为“在大鹿半岛潮汐带观察到的动物”的教科书。

It is one of the most important scientific programs for conservation of marine species and coastal environments to clarify the distribution and change of species composition among seasons and years in the coastal intertidal zones of complex environmental area. In this project, the distributions of species were surveyed in the 4 locations of 3 area in Oshika peninsula where warm and cold currents are mixed. Also, genetic differences were detected among morphologically similar species and genetic variability was demonstrated in the two common star fishes, Asterina pectinifera and A. amurensis, using isozyme markers.As results, a variety of species has been observed in the 4 localities of 3 areas in Oshika peninsula. The distribution of them was not drastically changed among different seasons and different years, but two star fishes were observed much more in summer season than in winter season. Compositions of species were similar among the localities, but in Koshidakaganngara (Tegula restica) was distributed much more in southern part than in northern part of Oshika peninsula. From the results, composition of species in the areas of Oshika peninsula could be one of the valuable index of environmental change.Isozyme analysis was performed for detection of morphologically similar specimens. Clear genetic divergence was observed among Polyplacophora species, and genetic identity was observed among color variations of Polytropa spp. High genetic variability was observed in both two star fish species compare with in average of molluscan species. Isozyme marker is considered to be usable genetic marker for detecting species and genetic characterization such as genetic variability.We will be publish a text book titled "Animals observed in the tidal zone of Oshika peninsula", on the results of this project in the year, 2001.