Data from: Genetic diversity and connectivity within Mytilus spp. in the subarctic and Arctic

Climate changes in the Arctic are predicted to alter distributions of marine species. However, such changes are difficult to quantify because information on present species distribution and the genetic variation within species is lacking or poorly examined. Blue mussels, <i>Mytilus</i> spp. are ecosystem engineers in the coastal zone globally. In order to improve knowledge of distribution and genetic structure of the <i>Mytilus edulis</i> complex in the Arctic, we analyzed 81 SNPs in 534 <i>Mytilus</i> spp. individuals sampled at 13 sites to provide baseline data for distribution and genetic variation of <i>Mytilus</i> mussels in the European Arctic. </i>Mytilus edulis</i> was the most abundant species found with a clear genetic split between populations in Greenland and the Eastern Atlantic. Surprisingly, analyses revealed the presence of <i>M. trossulus</i> in high Arctic NW Greenland (77°N) and <i>M. galloprovincialis</i> or their hybrids in SW Greenland, Svalbard and the Pechora Sea. Furthermore, a high degree of hybridization and introgression between species was observed. Our study highlights the importance of distinguishing between congener species, which can display local adaptation and suggests that information on dispersal routes and barriers are essential for accurate predictions of regional susceptibility to range expansions or invasions of boreal species in the Arctic.北极气候变化预计将改变海洋物种的分布格局。然而，此类变化难以量化，原因在于当前物种分布及物种内遗传变异的相关数据要么缺失，要么缺乏充分的研究。蓝贻贝属（<i>Mytilus</i> spp.）是全球沿海区域的生态系统工程师（ecosystem engineer）。为加深对北极地区紫贻贝（<i>Mytilus edulis</i>）复合类群分布与遗传结构的认知，本研究对13个采样点的534份蓝贻贝属个体进行了81个单核苷酸多态性（Single Nucleotide Polymorphism, SNP）位点分析，旨在为欧洲北极区域蓝贻贝属的分布与遗传变异提供基准数据。研究发现紫贻贝为优势物种，其格陵兰种群与东大西洋种群之间存在显著的遗传分化。令人意外的是，分析结果显示在北极西北部格陵兰海域（北纬77°）存在厚壳贻贝（<i>M. trossulus</i>），而在格陵兰西南部、斯瓦尔巴群岛及佩乔拉海区域则发现了地中海贻贝（<i>M. galloprovincialis</i>）或其杂交个体。此外，研究还观测到物种间存在高度的杂交与基因渐渗现象。本研究强调了区分同属物种的重要性——这类物种往往表现出局部适应性，并指出，要精准预测北极地区北方物种的分布扩张或入侵对区域的影响，明确其扩散路径与阻隔因素是不可或缺的关键信息。