Under the radar: genetic assessment of Rio Grande Shiner (Notropis jemezanus) and Speckled Chub (Macrhybopsis aestivalis), two Rio Grande basin endemic cyprinids that have experienced recent range contractions

The Rio Grande drainage of the southwestern United States and Mexico has undergone intense anthropogenic alteration by water diversions, extraction and associated habitat changes. These alterations have disproportionately impacted the pelagic broadcast spawning guild of minnows (pelagophils). Several Rio Grande endemic pelagophils, including the co-occurring Rio Grande Shiner (Notropis jemezanus) and Speckled Chub (Macrhybopsis aestivalis), have experienced dramatic recent range-wide declines yet have slipped under the radar of conservation efforts. The status of N. jemezanus and M. aestivalis in the Rio Grande and Pecos River was evaluated and standing genetic variation were characterized. Genetic evidence indicates that populations of both species found in the Rio Grande and Pecos River are genetically distinct. Additionally, 159 outlier loci were identified in M. aestivalis suggesting possible local adaptation in the Rio Grande and Pecos River populations. Though range-wide genetic d...

美国西南部及墨西哥境内的里奥格兰德河（Rio Grande）流域，已因引水工程、水资源抽取及伴随的栖息地改变遭受了强烈的人为改造。此类改造对远洋抛洒产卵型雅罗鱼功能群（pelagophils）造成了不成比例的负面影响。多种里奥格兰德河特有远洋产卵型鱼类，包括同期分布的里奥格兰德银鲦（Rio Grande Shiner，Notropis jemezanus）与斑点雅罗鱼（Speckled Chub，Macrhybopsis aestivalis），近期经历了全域性的种群急剧衰退，却始终未被保护工作纳入关注视野。本研究对里奥格兰德河与佩科斯河（Pecos River）中的N. jemezanus及M. aestivalis种群现状开展了评估，并对其现存遗传变异进行了表征。遗传证据显示，这两个物种在里奥格兰德河与佩科斯河中的种群均具有遗传分化特征。此外，研究在M. aestivalis中鉴定出159个异常位点（outlier loci），暗示其里奥格兰德河与佩科斯河种群可能存在局部适应。尽管全域遗传...