Data from: Fish faunal provinces of the conterminous United States of America reflect historical geography and familial composition

Although the conterminous USA has a long history of ichthyological exploration, the description of biogeographical provinces has been ad hoc. In this study we quantitatively determined fish faunal provinces and interpreted them in the context of the geological history of North America. We also evaluated influences of major river basin occupancy and contemporary environmental factors on provincial patterns. Our data set comprised 794 native fishes, which we used to generate a presence and absence matrix for U.S. Geological Survey (USGS) four-digit hydrologic units. Three nested data sets were analysed separately: primary freshwater families, continental freshwater families (including primary and secondary families) and all freshwater families (including primary, secondary and peripheral families). We used clustering analysis to delimit faunal breaks and one-way analysis of similarity (ANOSIM) to determine significance among clusters (i.e. provinces). We used an indicator-species analysis to identify species that contributed most to province delineations and a similarity-percentage (SIMPER) analysis to describe the relative influence of representatives from each category (i.e. primary, secondary, peripheral) on provincial boundaries. Lastly, we used a parsimony redundancy analysis to determine the roles of historical (i.e. major river basin) and contemporary environmental factors in shaping provinces. Analysis of the nested data sets revealed lessening provincial structure with inclusion of more families. There were 10 primary freshwater provinces, 9 continental freshwater provinces and 7 all freshwater provinces. Major basin occupancy, but not contemporary environmental factors, explained substantial variance in faunal similarities among provinces. However, provincial boundaries did not conform strictly to modern river basins, but reflected river-drainage connections of the Quaternary. Provinces represent broad-scale patterns of endemism and provide a starting point for future studies. Relative malleability of province boundaries in the continental interior highlights this region as biogeographically diverse and dynamic. Interior-core provinces of this region (Central Gulf Coastal Plains, Northern Interior) have not been recognized previously and warrant further study.尽管美国本土（conterminous USA）的鱼类学考察历史悠久，但此前对其鱼类动物地理分区（fish faunal provinces）的划定均为不成体系的临时方案。本研究通过定量方法明确了鱼类动物地理分区，并结合北美地质历史对其进行解读；同时评估了主要流域占据格局与当代环境因子对分区格局的影响。 本数据集涵盖794种本土鱼类，据此构建了美国地质调查局（U.S. Geological Survey, USGS）四位水文单元的物种存在-缺失矩阵。我们将数据集拆分为三个嵌套数据集分别开展分析：淡水原初科（primary freshwater families）、大陆淡水科（continental freshwater families，包含原初与次级淡水科）以及全部淡水科（all freshwater families，包含原初、次级与边缘淡水科）。 研究采用聚类分析（clustering analysis）界定动物区系分界（faunal breaks），并通过单因素相似性分析（Analysis of Similarity, ANOSIM）检验聚类结果（即各分区）间的显著性差异；利用指示物种分析（indicator-species analysis）识别对分区划定贡献最大的物种，并通过相似性百分比分析（Similarity Percentage, SIMPER）解析各类群（原初、次级、边缘类群）对分区边界的相对影响程度。最后，采用简约冗余分析（Parsimony Redundancy Analysis）明确历史因素（即主要流域格局）与当代环境因子在分区形成过程中的作用。 对嵌套数据集的分析显示，随着纳入的类群增多，分区结构的显著性逐渐降低。本研究共划定10个淡水原初分区、9个大陆淡水分区与7个全部淡水分区。主要流域格局能够解释分区间动物区系相似性的显著变异，但当代环境因子则无此效应。不过，分区边界并未完全契合现代流域格局，而是反映了第四纪时期的水系连通关系。 鱼类动物地理分区体现了大尺度的特有性（endemism）格局，可为后续研究提供基础框架。北美内陆区域的分区边界具有较高可塑性，表明该区域具有丰富且动态的生物地理特征。该区域的内陆核心分区——墨西哥湾中部沿海平原、北部内陆区——此前尚未被识别，亟需开展进一步研究。