Schönhuth Susana, Beachum Collin E, Knouft Jason H, Mayden Richard L
Department of Biology, Saint Louis University, 3507 Laclede Avenue, St. Louis, MO 63103, USA. phone: (314) 997-3932; Fax: (314) 977-3658.; Email:
Zootaxa. 2016 Sep 14;4168(1):38-60. doi: 10.11646/zootaxa.4168.1.2.
This study represents a phylogenetic analysis of Pimephales notatus, a widely distributed North American cyprinid fish species, using one mitochondrial (cytb) and two nuclear (S7 and Rag1) genes. Despite the broad geographic distribution of this species that includes independent basins, results suggest a largely drainage-independent genetic structure. Results reveal a well-supported lineage in the Ozark Highlands, which is highly divergent from the remaining populations and may represent a long-term isolated lineage that should be considered as a separate conservation and management unit. All other remaining populations comprised a widely distributed lineage, covering most of the distribution for the species (from the Red River and tributaries of the Great Lakes in the north to the lower Mississippi and Mobile basin in the south, and from the Missouri River in the west to the Chesapeake and Albemarle Sound basins in the east). Phylogenetic, genetic diversity, and biogeographical data suggest that this wide-ranging lineage could have experienced a recent expansion to northern areas where populations exhibit little genetic variation. Results from molecular analyses reveal a distinctive lineage in the Ozarks and suggest that there is need for morphological analyses within P. notatus to determine its taxonomic status.
本研究利用一个线粒体基因（细胞色素b）和两个核基因（S7和Rag1），对北美广泛分布的鲤科鱼类钝吻真小鲤进行了系统发育分析。尽管该物种地理分布广泛，涵盖了独立的流域，但结果表明其遗传结构在很大程度上不依赖于水系。结果显示，奥沙克高地存在一个得到充分支持的谱系，它与其他种群高度分化，可能代表一个长期隔离的谱系，应被视为一个单独的保护和管理单元。所有其他剩余种群构成一个广泛分布的谱系，覆盖了该物种的大部分分布范围（从北部的红河和五大湖支流到南部的密西西比河下游和莫比尔盆地，以及从西部的密苏里河到东部的切萨皮克湾和阿尔伯马尔湾流域）。系统发育、遗传多样性和生物地理数据表明，这个分布广泛的谱系可能近期向北部地区扩张，那里的种群遗传变异很小。分子分析结果揭示了奥沙克地区一个独特的谱系，并表明需要对钝吻真小鲤进行形态学分析以确定其分类地位。
