Abstract. The perceived cosmopolitanism of polychaete worms could be an artefact of historical factors such as poor original species descriptions, lack of type material and the European taxonomic bias, to name a few. Thus, it is possible that several cosmopolitan species hide complexes of cryptic and pseudocryptic species. Two putative cosmopolitan species, Platynereis dumerilii and Platynereis australis, collected in South Africa were investigated here (1) to determine whether the South African taxa are conspecific with the morphologically identical taxa from France and New Zealand (the respective type localities of P. dumerilii and P. australis), (2) to compare the South African species morphometrically to determine whether their morphological characters are reliable enough to separate them, and (3) to investigate whether these species have geographically structured populations along the coast of South Africa. Molecular data (COI and ITS1) confirm that P. dumerilii and P. australis do not occur in South Africa. Instead, the South African taxon formerly thought to be Platynereis dumerilii is new and is described here as Platynereis entshonae, sp. nov.; the identity of the other South African species is currently unresolved and is treated here as Platynereis sp. Surprisingly, Platynereis massiliensis (type locality: Marseilles) nested within the South African Platynereis sp. clade but, since it is part of a cryptic species complex in the Mediterranean, the name is considered doubtful. Morphological characters traditionally used to define these South African Platynereis species are not reliable as predefined morphological groupings do not match phylogenetic clades and principal component scores revealed no separation in morphological characters that could distinguish between them. Haplotype networks and phylogenetic trees revealed that P. entshonae, sp. nov. and Platynereis sp. have geographically structured populations along the South African coast.

中文翻译：

---

解决来自南非的两个神秘 Platynereis Kinberg 物种的分类学身份和遗传结构

摘要。多毛类蠕虫的世界主义可能是历史因素的产物，例如原始物种描述不佳，缺乏类型材料和欧洲分类学偏见，仅举几例。因此，可能有几个世界性物种隐藏了隐性和假隐性物种的复合体。这里对采集在南非的两个假定的世界性物种 Platynereis dumerilii 和 Platynereis australis 进行了调查 (1)，以确定南非分类群是否与来自法国和新西兰的形态相同的分类群（P. dumerilii 和 Platynereis P. australis), (2) 从形态计量学上比较南非物种，以确定它们的形态特征是否足够可靠以将它们分开，(3) 调查这些物种是否在南非海岸具有地理结构的种群。分子数据（COI 和 ITS1）证实 P. dumerilii 和 P. australis 在南非不存在。相反，以前被认为是 Platynereis dumerilii 的南非分类群是新的，这里被描述为 Platynereis entshonae, sp。十一月；其他南非物种的身份目前尚未确定，这里被视为 Platynereis sp。令人惊讶的是， Platynereis massiliensis（类型产地：马赛）嵌套在南非 Platynereis sp 中。但是，由于它是地中海神秘物种复合体的一部分，因此该名称被认为是可疑的。传统上用于定义这些南非 Platynereis 物种的形态特征是不可靠的，因为预定义的形态分组与系统发育进化枝不匹配，并且主成分分数显示没有可以区分它们的形态特征的分离。单倍型网络和系统发育树表明 P. entshonae, sp。十一月 和 Platynereis sp。沿南非海岸有地理结构的人口。