Were huge ancient lakes refugia for fishes distributed in Mogami River System ?

最近的地质资料表明，在400万至600万年前，在最近的莫加米河水系的上游和下游形成了两个巨大的湖泊。我们对可能在古湖泊周围进化的7种鱼类进行了种群遗传分析，并讨论了古湖泊对其进化的影响。七个物种中的两个可能是在古代湖泊附近形成的。另外3个物种的遗传结构在Mogami河水系与邻近河流种群或上游与下游种群之间存在差异，表明古湖泊的地理隔离影响了它们的遗传分化。在另外两个物种中，不同的遗传结构在种群之间无法识别。在相模河种群与Mogami河种群的比较中，无法通过引入来自不同河流系统的个体来进行明确的遗传分析。

The recent geological data suggests that two huge lakes had developed around the upper and lower reaches of recent Mogami River System during 4 - 6 million years ago. We conducted population genetic analyses of seven fishes that might be evolved around the ancient lakes, and discussed the influence of ancient lakes for their evolution. Two of the seven species had been probably speciated around the ancient lakes. In other three species, genetic structures were different between Mogami and adjacent river populations or between the upper and lower reach populations in Mogami River System, suggesting that geographical isolation by the ancient lakes had affected to their genetic differentiation. In other two species, distinctive genetic structures did not recognize between populations. In Sagami River populations to compare with Mogami River populations, clear genetic analyses could not do by remarkable introduction of individuals derived from different river systems.