Oncorhynchus masou, including subspecies of Oncorhynchus masou masou (yamame) and Oncorhynchus masou ishikawae (amago), is one of the salmonid groups impacted by human activity such as dam construction and release of non-native salmonids. In this study, we investigated the genetic structure of O. masou populations in the Sakawa and Sagami Rivers, Japan, by sequencing the mitochondrial control region. We hoped to identify genetically the O. masou populations specific to and originally native to Kanagawa Prefecture, where the two subspecies are thought to be present. The populations found in the upstream tributaries, where there has been no human impact and no upstream migration of fishes, were assumed to be descendants of the local O. masou populations in both river systems, and the morphological features seen here were similar to amago and yamame. However, both populations were genetically related to amago. In addition, only six haplotypes were detected in 315 individuals collected from 20 localities in the two river systems. Furthermore, haplotype diversity and nucleotide diversity of these populations were low, and high Fst values were observed. These results suggest that the population size is restricted and genetic diversity is decreasing in the O. masou populations of the Sakawa and Sagami Rivers.

Oncorhynchus masou，包括Oncorhynchus masou masou（yamame）和Oncorhynchus masou ishikawae（amago）的亚种，是受人类活动（例如大坝建设和非本地鲑鱼释放）影响的鲑鱼类之一。在这项研究中，我们通过对线粒体控制区进行测序，研究了日本佐川河和相模河中马苏种群的遗传结构。我们希望从基因上鉴定马苏神奈川县特有的原始种群，原本属于这两个亚种。在上游支流中发现的种群被认为是这两个河流系统中本地马苏种群的后代，这些种群没有人类的影响，也没有上游鱼类的迁移，在这里看到的形态特征类似于阿马戈河和阿马戈河。山梅 但是，这两个种群在遗传上均与阿玛戈有关。此外，在两个河流系统的20个地区收集的315个人中仅检测到6种单倍型。此外，这些种群的单倍型多样性和核苷酸多样性低，F st高。观察值。这些结果表明，佐川河和相模河的O. masou种群的种群规模受到限制，遗传多样性正在减少。