Centro de Investigación en Biodiversidad y Cambio Global (CIBC-UAM), Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, Cantoblanco, Madrid, Spain.
Animal Evolution and Biodiversity, Johann-Friedrich-Blumenbach Institute for Zoology & Anthropology, Georg-August-Universität Göttingen, Göttingen, Germany.
PLoS One. 2019 Apr 10;14(4):e0214211. doi: 10.1371/journal.pone.0214211. eCollection 2019.
Amblyosyllis is a worldwide distributed group of annelids mainly found in coastal environments. It is well known among the polychaete specialists mostly because of its notable beauty, showing bright colourful patterns and outstanding long and coiled appendices. Amblyosyllis is a monophyletic genus easy to identify due to its distinct diagnostic features; however, the species and their boundaries are, in most cases, not well defined. Herein, we provide an extensive sample of Amblyosyllis material (115 specimens) from several world geographic areas. We have studied the morphological features of each specimen and photographed them alive. Two mitochondrial DNA markers (COI and 16S) and one nuclear gene fragment (28S, D1 region) were sequenced. We performed phylogenetic analyses based on each DNA partition, as well as the combined data sets, obtaining congruent results. Species delimitation methods such as distance analyses, statistical parsimony networks and multi-rate Poisson tree processes were also applied. The combined results obtained from different methodologies and data sets are used to differentiate between, at least, 19 lineages compatible with the separately evolving meta-populations species concept. Four of these lineages are identified as nominal species, including the type species of Amblyosyllis, A. rhombeata. For three other lineages previously synonymized names are recovered, and seven lineages are described as new species. All of these species are described and supported by appropriate iconography. We recognize several morphological characters useful to identify species of Amblyosyllis, which in some cases should also be combined with molecular methods for species delineation. The genetic divergence in the genus is high, contrary to the morphological homogeneity observed. Two species show a wide geographical distribution, while the rest have a more restricted distribution. There are several examples of species with overlapping distribution patterns.
短须虫是一类广泛分布于世界各地的环节动物，主要生活在沿海环境中。由于其显著的美丽，表现出鲜艳的彩色图案和出色的长而卷曲的附肢，短须虫在多毛类专家中广为人知。短须虫是一个单系属，由于其独特的诊断特征，很容易识别；然而，在大多数情况下，物种及其界限并没有得到很好的定义。本文提供了来自多个世界地理区域的广泛的短须虫材料样本（115 个标本）。我们研究了每个标本的形态特征，并对其进行了活体拍照。我们对两个线粒体 DNA 标记（COI 和 16S）和一个核基因片段（28S、D1 区）进行了测序。我们基于每个 DNA 分区以及组合数据集进行了系统发育分析，获得了一致的结果。还应用了物种划分方法，如距离分析、统计简约网络和多速率泊松树过程。从不同方法和数据集获得的组合结果用于区分至少 19 个与单独进化的元种群物种概念相兼容的谱系。其中 4 个谱系被确定为命名种，包括短须虫的模式种 A. rhombeata。另外 3 个谱系恢复了以前的同义词，还有 7 个谱系被描述为新种。所有这些物种都有适当的插图进行描述和支持。我们识别出了几个有助于识别短须虫物种的形态特征，在某些情况下，这些特征还应与分子方法结合用于物种划分。该属的遗传分化很高，与观察到的形态同质性相反。有两个物种分布广泛，而其余物种的分布范围较窄。有几个例子表明物种分布模式存在重叠。
