Systematics of Fishes of Subfamily Lctiobinae (Teleostomi: Catostomidae)

杜兰大学的Henry Bart博士、David Hurley博士和Royal Suttkus博士被授予研究水牛亚科(水牛亚科和吸瓜亚科)鱼类的分类学和进化关系。按照目前的定义，该亚科包括七到八个活着的物种，分布在北美东部和墨西哥。然而，当前的分类法存在问题。大多数现代工人认为，这个群体比目前公认的要多样化得多。Ictiobines是大型河流生态系统的重要组成部分。它们扮演着重要的角色，将小型无脊椎动物从海底沉积物中过滤出来，并将这些生物转化为鱼的生物量。Ictiobines(尤其是Ictiobus属水鱼)在其活动范围的许多地方也是人类的重要食用鱼。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、对它们所居住的大河的广泛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。人类对大型河流栖息地的改造可能会导致密切相关物种一起出现的杂交问题。如果不很好地了解亚科的自然多样性和杂交对这种多样性的影响，就很难满足ictiobines的保护需求。这笔赠款的研究人员将研究目前公认的ictiobine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检索表，以帮助其他人进行物种鉴定。他们将对ictiobines的线粒体和核基因组的部分进行测序，以评估遗传差异的程度、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，他们将利用系统发育来研究种群内的形态进化和物种形成模式。该项目汇集了一名在传统分类修订方法方面拥有丰富经验的高级鱼类分类学家、一名熟悉现代系统方法和数据分析的初级分类学家/系统学家，以及一名对包括分子分类学在内的大量分子技术经验丰富的分子生物学家。

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.