Application of genetic data to species delimitation often builds confidence in delimitations previously hypothesized using morphological, ecological, and geographic data and frequently yields recognition of previously undescribed cryptic diversity. However, a recent critique of genomic data-based species delimitation approaches is that they have the potential to conflate population structure with species diversity, resulting in taxonomic oversplitting. The need for an integrative approach to species delimitation, in which molecular, morphological, ecological, and geographic lines of evidence are evaluated together, is becoming increasingly apparent. Here, we integrate phylogenetic, population genetic, and coalescent analyses of genome-wide sequence data with investigation of variation in multiple morphological traits to delimit species within the Antarctic barbeled plunderfishes (Artedidraconidae: Pogonophryne). Pogonophryne currently comprises 29 valid species, most of which are distinguished solely by variation in the ornamentation of the mental barbel that projects from the lower jaw, a structure previously shown to vary widely within a single species. However, our genomic and phenotypic analyses result in a dramatic reduction in the number of distinct species recognized within the clade, providing evidence to support the recognition of no more than six species. We propose to synonymize 24 of the currently recognized species with five species of Pogonophryne. We find genomic and phenotypic evidence for a new species of Pogonophryne from specimens collected in the Ross Sea. Our findings represent a rare example in which the application of molecular data provides evidence of taxonomic oversplitting on the basis of morphology, clearly demonstrating the utility of an integrative species delimitation framework.[ddRADseq; multispecies coalescent; Notothenioidei; SNPs; Southern Ocean.]

中文翻译：

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系统基因组物种划界显着降低了南极适应性辐射中的物种多样性

将遗传数据应用于物种划界通常会建立对先前使用形态学、生态学和地理数据假设的划界的信心，并经常产生对先前未描述的神秘多样性的认识。然而，最近对基于基因组数据的物种划分方法的批评是，它们有可能将种群结构与物种多样性混为一谈，从而导致分类过度分裂。对物种划界的综合方法的需求越来越明显，其中分子、形态、生态和地理证据线被一起评估。在这里，我们整合了系统发育、种群遗传、和合并分析全基因组序列数据，研究多种形态特征的变异，以划定南极有刺掠夺鱼（Artedidraconidae：Pogonophryne）内的物种。Pogonophryne 目前包括 29 个有效物种，其中大多数仅通过从下颌突出的精神触须装饰的变化来区分，这种结构以前显示在单个物种中差异很大。然而，我们的基因组和表型分析导致进化枝内识别的不同物种的数量急剧减少，提供了支持识别不超过六个物种的证据。我们建议将目前公认的 24 个物种与 5 个 Pogonophryne 同义化。我们从在罗斯海采集的标本中发现了一种新的 Pogonophryne 物种的基因组和表型证据。我们的研究结果代表了一个罕见的例子，其中分子数据的应用提供了基于形态学分类过度分裂的证据，清楚地证明了综合物种划界框架的效用。 [ddRADseq; 多物种聚结；诺特尼奥德伊; 单核苷酸多态性；南部海洋。]