The population structure and demographic history of a pelagic lumpsucker, Aptocyclus ventricosus, were investigated on the basis of sequence variation in the mitochondrial cytochrome b gene (1038 bp). The haplotype network clearly recovered two haplotype groups, consisting of western and eastern North Pacific individuals, except for some specimens collected from offshore of Tohoku, northern Japan. The geographic distribution of haplotypes suggests that the ocean currents in the North Pacific have shaped the population structure of the species after historical vicariant events between the Kuril Islands and Kamchatka Peninsula. In addition, the demographic histories of the two haplotype groups were quite different, suggesting that the western North Pacific group experienced a population expansion starting around 10,000 years ago, while the population size of the eastern North Pacific group has remained more stable.

中文翻译：

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远洋鲟Aptocyclus ventricosus的遗传种群结构和人口史

根据线粒体细胞色素 b 基因 (1038 bp) 的序列变异，研究了远洋肿块 Aptocyclus ventricosus 的种群结构和人口统计历史。除了从日本北部东北近海收集的一些标本外，单倍型网络清楚​​地恢复了两个单倍型组，由北太平洋西部和东部的个体组成。单倍型的地理分布表明，在千岛群岛和堪察加半岛之间的历史替代事件之后，北太平洋的洋流塑造了该物种的种群结构。此外，这两个单倍型群体的人口历史也大不相同，这表明西北太平洋群体在大约 10,000 年前开始经历了人口扩张，