Genetic connectivity plays a crucial role in shaping the geographic structure of species. Our aim in this study was to explore the pattern of genetic connectivity in Bursa scrobilator, an iconic marine caenogastropod with long-lived pelagic larvae. Our study was based on the analysis of DNA sequence data for the 658-bp barcoding fragment of the mitochondrial cytochrome c oxidase subunit I (COI) gene. This is the largest DNA sequence dataset assembled to date for B. scrobilator. These data confirm that the two recently described subspecies B. scrobilator scrobilator (Linnaeus, 1758), from the Mediterranean and Macaronesia, and B. s. coriacea (Reeve, 1844), from West Africa, constitute two evolutionarily significant units (ESUs). We found that for the nominal subspecies, the variation in morphology (shell, radula and gross anatomy) and DNA sequences was not geographically structured, and this agrees with what we would expect in a species with high connectivity at the larval stage. The divergence between the two subspecies cannot be easily explained by isolation by distance, and we would argue that one or more extrinsic factors may have played a role in isolating the two ESUs and maintaining that isolation.

中文翻译：

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腹足类动物具有长寿浮游幼虫的高遗传连通性

遗传连通性在塑造物种地理结构方面起着至关重要的作用。我们在这项研究中的目的是探索Bursa scrobilator（一种具有长寿上层幼虫的标志性海洋腹足纲动物）的遗传连通性模式。我们的研究基于对线粒体细胞色素C氧化酶亚基I（COI）基因658 bp条形码片段的DNA序列数据的分析。这是迄今为止为B. scrobilator组装的最大DNA序列数据集。这些数据证实了来自地中海和马卡罗尼西亚的两个最近描述的亚种B. scrobilator scrobilator（Linnaeus，1758）。ia科（里夫，1844年）来自西非，由两个具有进化意义的单位（ESU）组成。我们发现，对于名义上的亚种，形态（壳，小弓和大体解剖）和DNA序列的变化不是地理结构，这与我们期望的在幼体阶段具有高连通性的物种一致。这两个亚种之间的差异不能轻易通过距离隔离来解释，我们认为一个或多个外部因素可能在隔离两个ESU并保持这种隔离中发挥了作用。