Department of Botany and Zoology, Stellenbosch University, Private Bag X1, Matieland, 7602, South Africa.
Invertebr Syst. 2024 Feb;38. doi: 10.1071/IS23051.
A fine-scale phylogenetic and phylogeographic analysis of Peripatopsis lawrencei s.l. was conducted with both mitochondrial and nuclear DNA sequence data, using both external morphology and scanning electron microscopy of taxonomically important characters. A total of 119 sequences were used for the mitochondrial cytochrome c oxidase subunit I (COI ) whereas a single representative specimen from each locality was sequenced for the nuclear 18S rRNA locus. Phylogenetic analyses were conducted on the total COI data set and the combined COI + 18S rRNA data set using a Bayesian analysis and maximum likelihood analyses. For the combined DNA sequence data set, a divergence time estimation was further undertaken in BEAST and specimens placed in a phylogenetic framework including all the described Peripatopsis species from South Africa. In addition, a phylogeographic study was conducted exclusively on P. lawrencei s.s. (clade A) using an analysis of molecular variance and haplotype network. Phylogenetic results indicated that, at the Oubos sample locality, two highly distinct genetic lineages were present (clades A and B), whereas a divergence time estimation suggests a Miocene cladogenesis of the novel Oubos lineage. Marked phylogeographic structure was observed for P. lawrencei s.s. (restricted to clade A) across the distribution range with limited maternal dispersal. Morphologically, the two sympatric lineages at Oubos A and B differed in leg pair number, ventral colour and dorsal scale rank counts, as evident from scanning electron microscopy. Our results support the recognition of a distinct species that occurs in sympatry with P. lawrencei s.s. The new species, P. aereus sp. nov. (clade B) is described and the implication for fine-scale taxonomic studies on saproxylic taxa is discussed. ZooBank: urn:lsid:zoobank.org:pub:AB6E0BDA-7B5F-4FD3-A863-BA7C814E278C.
对 Peripatopsis lawrencei s.l. 进行了精细的系统发育和系统地理分析，使用了线粒体和核 DNA 序列数据，以及分类学上重要特征的外部形态和扫描电子显微镜。总共使用了 119 个序列进行线粒体细胞色素 c 氧化酶亚基 I（COI）的分析，而对于核 18S rRNA 基因座，每个地点都使用单个代表性标本进行了测序。使用贝叶斯分析和最大似然分析对总 COI 数据集和 COI+18S rRNA 联合数据集进行了系统发育分析。对于联合 DNA 序列数据集，在 BEAST 中进一步进行了分歧时间估计，并将标本置于包括南非所有描述的 Peripatopsis 物种的系统发育框架中。此外，仅对 P. lawrencei s.s.（A 分支）进行了系统地理研究，使用了分子方差分析和单倍型网络分析。系统发育结果表明，在 Oubos 采样地点，存在两个高度不同的遗传谱系（A 和 B 分支），而分歧时间估计表明，新的 Oubos 谱系在中新世发生了分支。对 P. lawrencei s.s.（仅限于 A 分支）在整个分布范围内观察到明显的系统地理结构，母体扩散有限。形态上，在 Oubos A 和 B 两个共生谱系在腿对数量、腹侧颜色和背鳞片等级计数方面存在差异，这从扫描电子显微镜中可以明显看出。我们的结果支持识别出一个与 P. lawrencei s.s. 共生的独特物种。新物种 P. aereus sp. nov.（B 分支）被描述，并讨论了对 saproxylic 分类群进行精细分类学研究的意义。ZooBank：urn:lsid:zoobank.org:pub:AB6E0BDA-7B5F-4FD3-A863-BA7C814E278C。
