Comparative study on the local populatoins of the East Asian temperate Sea basses

鲈科花鲈属（Lateolabrax）是东亚地区常见的经济鱼类。本属是该科中唯一的脊椎数目为35或36的属，被认为包括两个种L. latus和L.latus。最近，L. latus的刺在日本南部沿海变得常见，并且许多该种的幼鱼已经从中国进口。但是，没有分类学的审查，虽然已经知道物种之间的一些地理变异。因此，我们开始对日本落叶松的地理变异进行研究，并发现了一些关于日本落叶松地理变异的有趣的知识。中国沿海和朝鲜半岛西部的种群与日本沿海和朝鲜半岛半岛南部的种群在形态学和遗传学上应视为不同的种，前者应为花鲈，后者应为日本花鲈。另一方面，九州北方有明海的一个当地种群的线粒体DNA的基因组成不寻常，80%的个体的单倍型与中国花鲈相同，20%的个体的单倍型与日本花鲈相同。这表明有明海的种群可能起源于斑斑节蜱与斑节蜱的杂交种群，这在脊椎动物界是很少见的。因此，我们需要对有明海的种群进行更深入的研究。

Temperate sea basses, genus Lateolabrax of the Percichthyidae, are quite common commercial fishes in the East Asian countries. This genus is unique among the family in having 35 or 36 vertebral number and has been thought to encompass the two species L.japonicus and L.latus.Recently, acuaculture of L.japonicus has been getting common in the coasts of southern Japan and many juveniles of the species have been imported from China. But, there has been no taxonomic review although some geographic variations among the species have been known. Therefore, we started to study about the geographic variations of L.japonicus.As results of our study, we found some knowledges, which is quite interesting, about the geograhic variations of L.japonicus. The population occurring in the coasts of China and western Korean Peninsula and that in the coasts of Japan and southern Korean Peninsula should be treated as separate species from each other morphologically and genetically ; the former should be Lateolabrax maculatus and the latter L.japonicus. And another thing, one of the local population of Ariake Sea, northern part of Kyushu, has unusual gene composition of mitochandrial DNA ; haplotypes of 80% of the individuals are the same as those of L.maculatus (Chinese Lateolabrax), and those of 20% are the same as those of L.japonicus. This means the population of Ariake Sea may be originated from the hybridyzed population between L.maculatus and L.japonicus, which is quite unusualin the vertebrate world. Therefore, we need more advanced research about the population of Ariake Sea.