Leeches of the family Erpobdellidae are important members of benthic freshwater environments, where they are voracious predators of other invertebrates and an important source of nutrition for several species of vertebrates. Beset by a lack of reliable diagnostic morphological characters and destructive identification processes, molecular approaches have, in recent years, been employed to illuminate the relationships within this family, and DNA barcoding has been employed for identification purposes. However, an understanding of the levels of genetic variation across the geographic distributions of members of the genus is still lacking. Herein, we sequence the mitochondrial COI locus for 249 newly collected North American individuals, representing 5 species, as well as mitochondrial 12S rDNA, nuclear 18S rDNA, and nuclear 28S rDNA for a select subset of these. Our COI dataset was leveraged to detect potential cryptic species, and to calculate genetic distances as a proxy for the degree of gene flow between populations. Augmented by numerous sequences from GenBank, the multilocus dataset was used to reconstruct a phylogenetic hypothesis for worldwide members of the genus. Beyond corroborating previous overarching phylogenetic frameworks, our results show that an undescribed species that is morphologically and genetically similar to Erpobdella punctata exists in sympatry with this species - the new species has likely been overlooked in previous studies due to its morphological similarity with Erpobdella punctata. Erpobdella bucera is reported from Canada for the first time; and Erpobdella microstoma is newly reported from Saskatchewan and placed in a phylogeny for the first time. Finally, we find evidence for genetic structure in both E. cf. punctata and Erpobdella obscura that is correlated with major river drainage basin boundaries in North America.

中文翻译：

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Erpobdella（Annelida：Hirudinida：Erpobdelliformes）的遗传变异，伪密码学多样性和系统发育，重点是加拿大物种。

Erpobdellidae家族的水ches是底栖淡水环境的重要成员，在这里它们是其他无脊椎动物的贪食性掠食者，并且是几种脊椎动物的重要营养来源。由于缺乏可靠的诊断形态学特征和破坏性的鉴定过程，近年来，分子方法已被用于阐明该家族中的关系，并且DNA条形码已用于鉴定目的。但是，仍然缺乏对属成员地理分布中遗传变异水平的了解。在此，我们对代表5种物种的249个新近采集的北美个体的线粒体COI位点以及线粒体12S rDNA，核18S rDNA进行了测序，和核28S rDNA的选择子集。利用我们的COI数据集来检测潜在的神秘物种，并计算遗传距离，作为群体之间基因流动程度的代理。通过来自GenBank的众多序列的增强，多基因座数据集被用于为该属的全球成员重建系统发育假说。除了证实先前的总体系统发育框架外，我们的结果还显示，与该物种共存的形态学和遗传学相似的未描述物种与该物种共存-由于其与形态学相似，该新物种可能已在先前的研究中被忽略。加拿大首次报道了埃波氏杆菌。萨斯喀彻温省最近报道了小球藻，并首次将其置于系统发育中。最后，我们在两个大肠杆菌中找到了遗传结构的证据。punctata和Erpobdella obscura与北美主要的流域盆地边界相关。