The use of genetic markers in the context of conservation is largely being outcompeted by whole-genome data. Comparative studies between the two are sparse, and the knowledge about potential effects of this methodology shift is limited. Here, we used whole-genome sequencing data to assess the genetic status of peripheral populations of the wels catfish (Silurus glanis), and discuss the results in light of a recent microsatellite study of the same populations. The Swedish populations of the wels catfish have suffered from severe declines during the last centuries and persists in only a few isolated water systems. Fragmented populations generally are at greater risk of extinction, for example due to loss of genetic diversity, and may thus require conservation actions. We sequenced individuals from the three remaining native populations (Båven, Emån, and Möckeln) and one reintroduced population of admixed origin (Helge å), and found that genetic diversity was highest in Emån but low overall, with strong differentiation among the populations. No signature of recent inbreeding was found, but a considerable number of short runs of homozygosity were present in all populations, likely linked to historically small population sizes and bottleneck events. Genetic substructure within any of the native populations was at best weak. Individuals from the admixed population Helge å shared most genetic ancestry with the Båven population (72%). Our results are largely in agreement with the microsatellite study, and stresses the need to protect these isolated populations at the northern edge of the distribution of the species.

在保护方面使用遗传标记在很大程度上被全基因组数据所取代。两者之间的比较研究很少，关于这种方法转变的潜在影响的知识也很有限。在这里，我们使用全基因组测序数据来评估wels catfish (Silurus glanis ) 外围种群的遗传状态), 并根据最近对同一人群进行的微卫星研究讨论结果。在过去的几个世纪里，瑞典的威尔士鲶鱼种群数量急剧下降，并且仅在少数孤立的水系统中存在。分散的种群通常面临更大的灭绝风险，例如由于遗传多样性的丧失，因此可能需要采取保护行动。我们对剩余的三个本地种群（Båven、Emån 和 Möckeln）和一个重新引入的混合起源种群 (Helgeå) 的个体进行了测序，发现 Emån 的遗传多样性最高，但总体较低，种群之间的差异很大。没有发现近期近亲繁殖的迹象，但所有种群中都存在相当数量的短程纯合子，可能与历史上人口规模小和瓶颈事件有关。任何本地种群中的遗传亚结构充其量是微弱的。来自混合种群 Helge å 的个体与 Båven 种群共享大部分遗传血统 (72%)。我们的结果在很大程度上与微卫星研究一致，并强调需要保护物种分布北部边缘的这些孤立种群。