Coral Conservation and Research Group (CORE), Trace and Environmental DNA Laboratory (TrEnD), School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia.
Coral Conservation and Research Group (CORE), Trace and Environmental DNA Laboratory (TrEnD), School of Molecular and Life Sciences, Curtin University, Bentley, Western Australia 6102, Australia.
Mol Phylogenet Evol. 2022 Jul;172:107469. doi: 10.1016/j.ympev.2022.107469. Epub 2022 Mar 26.
Scleractinian corals are a diverse group of ecologically important yet highly threatened marine invertebrates, which can be challenging to identify to the species level. An influx of molecular studies has transformed scleractinian systematics, highlighting that cryptic species may be more common than previously understood. In this study, we test the hypothesis that Plesiastrea versipora (Lamarck, 1816), a species currently considered to occur throughout the Indo-Pacific in tropical, sub-tropical and temperate waters, is a single species. Molecular and morphological analyses were conducted on 80 samples collected from 31 sites spanning the majority of the species putative range and twelve mitogenomes were assembled to identify informative regions for phylogenetic reconstruction. Congruent genetic data across three gene regions supports the existence of two monophyletic clades aligning with distinct tropical and temperate provenances. Multivariate macromorphological analyses based on 13 corallite characters provided additional support for the phylogeographic split, with the number of septa and corallite density varying across this biogeographic divide. Furthermore, micromorphological and microstructural analyses identified that the temperate representatives typically develop sub-cerioid corallites with sparse or absent coenosteal features and smooth septal faces. In contrast, tropical representatives typically develop plocoid corallites separated by a porous dissepimental coenosteum and have granulated septal faces. These data suggest that at least two species exist within the genus PlesiastreaMilne Edwards & Haime, 1848. Based on examination of type material, we retain the name Plesiastrea versipora (Lamarck, 1816) for the temperate representatives of the genus and resurrect the name Plesiastrea peroniMilne Edwards & Haime, 1857 for the tropical members. This study highlights how broadly distributed hard coral taxa still need careful re-examination through an integrated systematics approach to better understand their phylogeographic patterns. Furthermore, it demonstrates the utility of integrating micro-, macro-morphological and genetic datasets, and the importance of type specimens when dealing with taxonomic revisions of scleractinian taxa.
石珊瑚是一个生态重要但高度受威胁的海洋无脊椎动物多样性群体，其物种鉴定具有挑战性。大量的分子研究改变了石珊瑚系统发育学，突显了隐种可能比以前理解的更为普遍。在这项研究中，我们检验了假设，即 Plesiastrea versipora（拉马克，1816 年），一种目前被认为存在于整个印度洋-太平洋地区的热带、亚热带和温带水域的物种，是一个单一的物种。对从 31 个地点采集的 80 个样本进行了分子和形态分析，这些地点跨越了该物种假定范围的大部分地区，并组装了 12 个线粒体基因组，以确定用于系统发育重建的信息区域。三个基因区域的一致遗传数据支持两个单系群的存在，这些群与明显的热带和温带起源相一致。基于 13 个珊瑚虫特征的多变量宏观形态分析为系统地理学分裂提供了额外的支持，瓣间隔数和珊瑚虫密度在这个生物地理分界线上有所不同。此外，微形态学和微观结构分析表明，温带代表通常发育具有稀疏或不存在珊瑚骨特征的亚珊瑚虫状珊瑚虫，并且具有光滑的瓣间隔面。相比之下，热带代表通常发育具有多孔分隔珊瑚骨的 plocoid 珊瑚虫，并且具有粒状瓣间隔面。这些数据表明，至少有两个种存在于 Plesiastrea 属中。基于对模式标本的检查，我们保留了 Plesiastrea versipora（拉马克，1816 年）的名称用于该属的温带代表，恢复了 Plesiastrea peroniMilne Edwards & Haime, 1857 的名称用于热带成员。这项研究强调了广泛分布的硬珊瑚类群仍然需要通过综合系统发育方法进行仔细重新检查，以更好地了解它们的地理分布模式。此外，它展示了整合微观、宏观形态和遗传数据集的实用性，以及在处理石珊瑚类群的分类修订时模式标本的重要性。
