Population genomics reveals seahorses (Hippocampus erectus) of the western mid-Atlantic coast to be residents rather than vagrants

Understanding population structure and areas of demographic persistence and transients is critical for effective species management. However, direct observational evidence to address the geographic scale and delineation of ephemeral or persistent populations for many marine fishes is limited. The Lined seahorse (Hippocampus erectus) can be commonly found in three western Atlantic zoogeographic provinces, though inhabitants of the temperate northern Virginia Province are often considered tropical vagrants that only arrive during warm seasons from the southern provinces and perish as temperatures decline. Although genetics can locate regions of historical population persistence and isolation, previous evidence of Virginia Province persistence is only provisional due to limited genetic sampling (i.e., mitochondrial DNA and five nuclear loci). To test alternative hypotheses of historical persistence versus the ephemerality of a northern Virginia Province population we used a RADseq generate...解析种群结构、种群统计学意义上的存续区域与临时居留区域，对于开展高效的物种管理工作至关重要。然而，针对多数海洋鱼类的临时或永久种群的地理分布尺度与划定边界，目前直接观测证据仍较为有限。线纹海马（*Hippocampus erectus*）广泛分布于西大西洋的3个动物地理区内，但栖息于弗吉尼亚北部温带区的种群常被视作热带漂迁类群：它们仅在暖季从南部地理区迁入，随水温下降而死亡。尽管遗传学手段可识别历史上的种群存续与隔离区域，但此前关于弗吉尼亚区种群存续的证据仅为暂时性结论，原因在于遗传采样规模有限（仅覆盖线粒体DNA与5个核基因座）。为验证“弗吉尼亚北部温带区种群为历史存续种群”与“该种群为临时居留类群”这两种对立假说，本研究采用限制性位点相关DNA测序（RADseq）技术开展