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

弄清环境复杂的滨海潮间带物种组成的季节分布和年际变化，是保护海洋物种和海岸环境的重要科学课题之一。本项目对大岛半岛冷暖流交汇的3个区域的4个地点的物种分布进行了调查。此外，利用同工酶标记检测了形态相似的物种间的遗传差异，并利用同工酶标记分析了两种常见的星鱼--海星和海星的遗传变异。结果表明，在Oshika半岛3个地区的4个地点都观察到了种类的多样性。它们的分布在不同季节和不同年份之间变化不大，但夏季观察到的两种星鱼明显多于冬季。不同地区的种类组成相似，但在小岛半岛南部的分布明显多于北部。结果表明，Oshika半岛的物种组成可能是环境变化的有价值的指标之一。同工酶分析用于检测形态相似的标本。不同物种间存在明显的遗传分化，不同颜色的多年生多年生草种间存在明显的遗传一致性。与软体动物物种的平均遗传变异性相比，两种海星鱼都具有较高的遗传变异性。同工酶标记被认为是检测物种和遗传特征(如遗传多样性)的有用的遗传标记。我们将于2001年出版一本名为《在奥什卡半岛潮汐带观察到的动物》的教科书，介绍这一项目的结果。

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.