Waraniak Justin M, Eackles Michael S, Keagy Jason, Smith Geoffrey D, Schall Megan, Stark Sydney, White Shannon L, Kazyak David C, Wagner Tyler
Pennsylvania Cooperative Fish and Wildlife Research Unit, Department of Ecosystem Science and Management, The Pennsylvania State University, University Park, Pennsylvania, USA.
U.S. Geological Survey Eastern Ecological Science Center, Kearneysville, West Virginia, USA.
J Fish Biol. 2024 Dec;105(6):1614-1627. doi: 10.1111/jfb.15888. Epub 2024 Aug 12.
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 H = 0.504), although we detected no evidence of substantial inbreeding (F = -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.
对入侵种群进行群体遗传学分析，可为引入源、扩散途径及其种群历史提供有价值的见解。平头鲶（Pylodictis olivaris）是一种繁殖力强的入侵物种，具有高繁殖力、远距离扩散能力以及食鱼性的摄食习性，可能导致本地鱼类种群数量下降。在本研究中，我们分析了大西洋中部地区入侵的平头鲶的遗传学特征，以评估它们的连通性，并尝试重建引入种群的历史。基于对13个微卫星位点的评估，萨斯奎哈纳河水系（N = 537）、斯库尔基尔河（N = 33）和特拉华河（N = 1）的平头鲶遗传多样性较低（全局H = 0.504），尽管我们未检测到明显近亲繁殖的证据（F = -0.083至0.022）。来自这些不同水系的平头鲶在基因上是有差异的，表明是独立引入的。然而，每个水系内的种群结构要弱得多，呈现出高连通性的模式，并有一些距离隔离的证据。来自萨斯奎哈纳河和斯库尔基尔河的平头鲶显示出近期存在遗传瓶颈的证据，并且种群统计学模型与历史记录一致，这表明种群是由少数个体组成的近期奠基者事件所建立的。我们的结果显示了少量引入平头鲶所带来的风险，一旦种群建立，它们就能广泛传播，并强调了预防和灵敏的早期检测方法对于防止未来平头鲶扩散的重要性。
