Abstract：
Population genetic analysis of invasive populations can provide valuable insights into the source of introductions, pathways for expansion, and their demographic histories. Flathead catfish (Pylodictis olivaris) are a prolific invasive species with high fecundity, long-distance dispersal, and piscivorous feeding habits that can lead to declines in native fish populations. In this study, we analyse the genetics of invasive P. olivaris in the Mid-Atlantic region to assess their connectivity and attempt to reconstruct the history of introduced populations. Based on an assessment across 13 microsatellite loci, P. olivaris from the Susquehanna River system (N = 537), Schuylkill River (N = 33), and Delaware River (N = 1) have low genetic diversity (global Hobs = 0.504), although we detected no evidence of substantial inbreeding (FIS = -0.083 to 0.022). P. olivaris from these different river systems were genetically distinct, suggesting separate introductions. However, population structure was much weaker within each river system and exhibited a pattern of high connectivity, with some evidence of isolation by distance. P. olivaris from the Susquehanna and Schuylkill rivers showed evidence for recent genetic bottlenecks, and demographic models were consistent with historical records, which suggest that populations were established by recent founder events consisting of a small number of individuals. Our results show the risk posed by small introductions of P. olivaris, which can spread widely once a population is established, and highlight the importance of prevention and sensitive early detection methods to prevent the spread of P. olivaris in the future.
摘要：
对入侵人群的群体遗传分析可以为引进来源提供有价值的见解，扩张途径，和他们的人口历史。平头cat鱼（Pylodictisolivaris）是一种多产的入侵物种，具有高繁殖力，长距离传播，和食鱼的摄食习惯可能导致本地鱼类种群减少。在这项研究中,我们分析了大西洋中部地区侵袭性Olivaris的遗传学，以评估它们的连通性，并试图重建引入种群的历史。基于对13个微卫星位点的评估，来自萨斯奎哈纳河系统的奥利瓦里斯(N=537)，Schuylkill河（N=33），特拉华河(N=1)遗传多样性低(全球Hobs=0.504)，尽管我们没有检测到大量近亲繁殖的证据（FIS=-0.083至0.022）。来自这些不同河流系统的奥利瓦里斯在遗传上是不同的，建议单独介绍。然而,每个河流系统内的人口结构要弱得多，并表现出高度连通性的模式，有一些孤立的证据。来自Susquehanna和Schuylkill河流的Olivaris显示了最近遗传瓶颈的证据，人口统计模型与历史记录一致，这表明人口是由最近的创始人事件建立的，这些事件由少数人组成。我们的结果表明，少量引入Olivaris会带来风险，一旦人口建立，它就会广泛传播，并强调了预防和敏感的早期检测方法的重要性，以防止未来的传播。
