The octocoral genus Chrysogorgia (Duchassaing and Michelotti, 1864) contains 81 nominal species that are ecologically important components of benthic communities. Taxonomic examination of a large set of samples revealed many provisional new species, exhibiting a wide range of morphological variation. We established nine, distinct morphological groups of Chrysogorgia s.l. that were hypothesized to represent distinct genera. Here, we applied a recently developed universal target enrichment bait method for octocoral exons and ultraconserved elements (UCEs) on 96 specimens varying in morphology, collection ages and DNA quality and quantity to determine whether there was genetic support for these morphologically defined groups. Following Illumina sequencing and SPAdes assembly we recovered 1,682 of 1,700 targeted exon loci and 1,333 of 1,340 targeted UCE loci. Locus recovery per sample was highly variable and significantly correlated with time since specimen collection (2–60 years) and DNA quantity and quality. Phylogenetically informative sites in UCE and exon loci were ∼35% for 50% and 75% taxon-occupancy matrices. Maximum likelihood analyses recovered highly resolved trees with topologies supporting the recognition of 11 candidate genera, corresponding with morphological groups assigned a priori, nine of which are novel. Our results also demonstrate that this target-enrichment approach can be successfully applied to degraded museum specimens of up to 60 years old. This study shows that an integrative approach consisting of molecular and morphological methods will be essential to a proper revision of Chrysogorgia taxonomy and to understand regional diversity of these ecologically important corals.

中文翻译：

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Chrysogorgia (Alcyonacea: Octocorallia) 内的系统发育关系，Octocoral 的一种形态多样的属，使用目标富集方法揭示

八珊瑚属 Chrysogorgia (Duchassaing and Michelotti, 1864) 包含 81 个名义物种，它们是底栖群落的生态重要组成部分。大量样本的分类学检查揭示了许多临时新物种，表现出广泛的形态变异。我们建立了九个不同的 Chrysogorgia sl 形态群，假设它们代表不同的属。在这里，我们对 96 个形态、收集年龄和 DNA 质量和数量不同的标本应用了最近开发的通用目标富集诱饵方法，用于八珊瑚外显子和超保守元素 (UCE)，以确定这些形态学定义的群体是否存在遗传支持。在 Illumina 测序和 SPAdes 组装之后，我们回收了 1,700 个靶向外显子位点中的 1,682 个和 1 个中的 1,333 个，340 个目标 UCE 位点。每个样本的基因座恢复变化很大，并且与样本收集时间（2-60 年）以及 DNA 数量和质量显着相关。对于 50% 和 75% 的分类单元占用矩阵，UCE 和外显子位点中的系统发育信息位点约为 35%。最大似然分析恢复了具有支持识别 11 个候选属的拓扑的高分辨率树，对应于先验分配的形态组，其中九个是新的。我们的结果还表明，这种目标富集方法可以成功应用于长达 60 年的退化博物馆标本。