Systematics of Fishes of Subfamily Lctiobinae (Teleostomi: Catostomidae)

摘要/ abstract摘要：美国杜兰大学的Henry Bart， David Hurley和Royal Suttkus研究了Ictiobinae亚科鱼类的分类和进化关系（水牛鱼和卡普鱼）。根据目前的定义，这个亚科包括7到8个现存物种，分布在北美东部和墨西哥。然而，目前的分类法存在一些问题。大多数现代工人认为这个群体比目前所认识的要多样化得多。烟碱是大型河流生态系统的重要组成部分。它们在从底部沉积物中提取小型无脊椎动物并将这些生物转化为鱼类生物量方面发挥着重要作用。在其活动范围的许多地方，ictiobine（特别是水牛鱼，Ictiobus属）也是人类重要的食用鱼类。从历史上看，就总生物量而言，它们是北美东部大河中的主要鱼类群体。然而，近年来，由于污染、它们栖息的大河被大规模改造，以及生态相似的外来鲤鱼的成功，它们的数量一直在下降。人类对大河栖息地的改造可能会导致近亲物种杂交的问题。如果不能很好地了解伊硫宾亚科的自然多样性以及杂交对这种多样性的影响，将很难解决伊硫宾的保护需求。这项拨款的研究人员将检查目前已知的伊硫滨物种的形态和遗传变异。它们将正式描述任何新发现的物种，并将提供特征和分类钥匙，以帮助其他人进行物种识别。他们将对伊硫滨的部分线粒体和核基因组进行测序，以评估遗传分化的程度、种间杂交的程度和影响，以及物种之间的系统发育关系。最后，他们将使用系统发生学来检查群体内的形态进化和物种形成模式。该项目结合了一位在传统分类修订方法方面经验丰富的资深鱼类分类学家、一位熟悉现代系统方法和数据分析的初级分类学家/系统学家，以及一位在包括分子系统学在内的大量分子技术方面经验丰富的分子生物学家的才能。

ABSTRACTDEB-0237013A grant has been awarded to Drs. Henry Bart, David Hurley, and Royal Suttkus at Tulane University to study the taxonomy and evolutionary relationships of fishes in Subfamily Ictiobinae (buffalofishes and carpsuckers). As presently defined, the subfamily includes seven or eight living species, distributed throughout eastern North America and Mexico. However, there are problems with the current taxonomy. Most modern workers consider the group to be much more diverse than presently recognized. Ictiobines are an important component of large river ecosystems. They play an important role straining small invertebrates from bottom sediments and converting these organisms to fish biomass. Ictiobines (especially buffalofishes, genus Ictiobus) are also important food fishes for humans in many parts of their range. Historically, they were the dominant group of fishes in large rivers of eastern North America in terms of overall biomass. However, their numbers have been declining in recent years due to pollution, extensive modification of the large rivers they inhabit, and the success of ecologically similar, exotic carps. Human modification of large river habitats may be contributing to a problem of hybridization where closely related species occur together. It will be difficult to address conservation needs of ictiobines without a good understanding of natural diversity in the subfamily and the impact of hybridization on this diversity.The investigators on this grant will examine morphological and genetic variation within currently recognized ictiobine species. They will formally describe any newly discovered species, and will provide characters and taxonomic keys to aid others with species identification. They will sequence portions of the mitochondrial and nuclear genomes of ictiobines to assess degrees of genetic divergence, extent and impact of interspecific hybridization, and phylogenetic relationships among species. Lastly, they will use the phylogenies to examine morphological evolution and speciation patterns within the group. The project combines the talents of a senior fish taxonomist with extensive experience in traditional methods of taxonomic revision, a more junior taxonomist/systematist familiar with modern systematic methods and data analysis, and a molecular biologist experienced with the vast array of molecular techniques, including molecular systematics.