The common hermit crab Pagurus bernhardus (Linnaeus, 1758) is an abundant and ecologically important benthic crustacean in the northeastern Atlantic Ocean. While this species has been intensively studied in terms of its ecology, physiology, behavior, and larval development, knowledge about its population structure and demographic history is still lacking. We examined, for the first time, the genetic variability of P. bernhardus by analyzing two mitochondrial gene fragments (CO1 and 16S) from more than 150 specimens collected from various locations from the Iberian Peninsula to Norway. Our results provide evidence for a significant genetic structure according to the sampled regions for both genetic markers. Furthermore, a comprehensive demographic history reconstruction, mainly based on neutrality tests and a Bayesian Skyline Plot (CO1), revealed a recent demographic expansion of P. bernhardus that preceded the Last Glacial Maximum. Such pattern of retrieved demographic trend could have been likely a successive process to historical contraction of the species into potential climate refugia within the surveyed geographic spectrum.

中文翻译：

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对常见的寄居蟹Pagurus bernhardus（Linnaeus，1758）（十足目：Anomura：Paguridae）在东大西洋和北海的植物志和人口历史的初步了解

常见的寄居蟹Pagurus bernhardus（Linnaeus，1758年）是东北大西洋中丰富的，具有重要生态意义的底栖甲壳类动物。尽管已经对该物种的生态，生理，行为和幼体发育进行了深入研究，但仍缺乏有关其种群结构和人口历史的知识。我们首次检查了伯氏疟原虫的遗传变异性通过分析从伊比利亚半岛到挪威各地的150多个标本中的两个线粒体基因片段（CO1和16S）进行分析。我们的研究结果为根据两个遗传标记的采样区域提供了重要的遗传结构证据。此外，主要基于中立性测试和贝叶斯天际线图（CO1）进行的全面人口历史重建，揭示了伯纳德对虾的最近一次人口膨胀是在最后冰川期之前。所检索的人口趋势的这种模式可能是该物种历史收缩成所调查的地理范围内潜在的气候变迁的连续过程。