Comparative Molecular Phylogenetic Study on Speciation and Genetic Differentiation of Marine Organisms between the Pacific Ocean and the Japan Sea

为了揭示更新世大环境变化对日本海海洋生物的影响，采用分子系统发育方法分析了日本海各种海洋生物的种群结构。对日本海最具优势的深海底栖鱼——荷兰Bothricara hollandi的分析表明，该物种的种群由两个遗传上不同的群体组成，并且表明在末次冰期，土岛海峡附近没有发生剧烈的环境变化。日本圆壳类（Turbo (Batillus) cornutus）种群的清晰遗传结构形成于更新世并保存至今，而浮游期较长的潮间腹足类（Omphalinus pfeifferi）种群的遗传结构则显示形成于末次冰期结束后。在日本海分离出来的O.pfeifferi的个体被认为在相对较短的时间内成为了O.pfeifferi carpenteri亚种。一种直接发育的泥扁螺（Batillaria cumingi）在遗传结构上比同类的多形螺（Batillaria multiformis）和日本帽壳螺（Japanese turban shell）表现出更大的分化。一些浅水腹足动物，如Sulculus diversicolor、Astralium haematragum、Chlorostoma argyrostoma和Monodonta labio，在日本海和太平洋没有发现明显的遗传分化。这些结果表明，幼虫扩散能力对海洋物种遗传结构的形成具有重要意义。

In order to reveal effects of large enviromnental changes during the Pleistocene on marine organisms in the Japan Sea, population structures of various marine organisms were analyzed using molecular phylogenetic methods.The analysis of the most dominant deep-sea demersal fish of the Japan Sea, Bothricara hollandi, showed that populations of this species consist of the two genetically different groups and it was suggested that no drastic environmental change occurred near the Thushima Strait during the last glacial period.While the clear genetic structure of a population of the Japanese turban shell, Turbo (Batillus) cornutus, whose planktonic period is very short, formed during the Pleistocene and have been kept until now, the genetic structure of an intetidal gastropod wth much longer planktonic period, Omphalinus pfeifferi, was shown to have formed after the end of the last glacial period. Individuals of O.pfeifferi, which were isolated in the Japan Sea, are thought to have become the subspedes, O.pfeifferi carpenteri, in the relatively short period.A direct-developing mud flat snail, Batillaria cumingi, showed more diverged genetic structure than the congeneric planktonic species, B.multiformis as well as the Japanese turban shell. No clear genetic differentiation was detected between the Japan Sea and the Pacific for some shallow water gastropods, namely Sulculus diversicolor, Astralium haematragum, Chlorostoma argyrostoma and Monodonta labio.The present results suggest the importance of larval dispersal ability far the formation of the genetic structures of marine species.