The Mediterranean area, from southern Balkans to western Maghreb, is inhabited by the Potamon subgenus Euthelphusa, with three currently recognised species. The Maghrebian species P. (E.) algeriense is isolated from other Potamon species by the Mediterranean Sea and the Sahara Desert, and nearly no molecular data are currently available for this taxon. Present study investigated the mtDNA and nuDNA diversity in Potamon algeriense s.l. with the aims of exploring its molecular diversity pattern throughout its known distribution range, and testing the possible presence of cryptic taxa currently lumped under this binomen. The phylogenetic and DNA taxonomy analyses showed the presence of two well‐supported clades of species rank within P. algeriense s.l, with an eastern clade including the populations from Tunisia and Numidia, and a western, highly structured clade including the populations from central Algeria and Morocco. In agreement with a typical Maghrebian biogeographic pattern, the distribution of these two species shows a clear east–west divide, with a disjunction zone located in Kabylia, and a strong link between molecular diversity and segregation within different hydrographical basins is evident. The Maghreb thus proved to host an unexpectedly high genetic diversity of, and to constitute a biodiversity hot‐spot for, the Potamon subgenus Euthelphusa. In the light of the existence of two well‐characterised species currently lumped under P. algeriense s.l., and of their noteworthy molecular structuring, the status of Maghrebian Potamon populations should be re‐assessed for both the species present in the area, which are to be considered as independent management units.

中文翻译：

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来自北非的potamid淡水螃蟹的DNA分类学（十足目，Potamidae）

从巴尔干半岛南部到马格里布西部的地中海地区居住着 Potamon 亚属 Euthelphusa，目前有三个物种。Maghrebian 物种 P. (E.) algeriense 与地中海和撒哈拉沙漠的其他 Potamon 物种分离，目前几乎没有可用于该分类群的分子数据。本研究调查了 Potamon algeriense sl 中的 mtDNA 和 nuDNA 多样性，目的是探索其在其已知分布范围内的分子多样性模式，并测试目前归入该双名目下的神秘分类群的可能存在。系统发育和 DNA 分类学分析表明，在 P. algeriense sl 中存在两个得到充分支持的物种进化枝，一个东部进化枝包括来自突尼斯和努米迪亚的种群，以及一个西部进化枝，高度结构化的进化枝，包括来自阿尔及利亚中部和摩洛哥的种群。与典型的马格里布生物地理模式一致，这两个物种的分布显示出明显的东西分界线，分离带位于卡比利亚，分子多样性与不同水文流域内的分离之间的密切联系是显而易见的。马格里布因此被证明拥有出乎意料的高遗传多样性，并构成了 Potamon 亚属 Euthelphusa 的生物多样性热点。鉴于目前归入 P. algeriense sl 的两个特征明确的物种的存在，以及它们值得注意的分子结构，应重新评估该地区存在的两个物种的马格里布 Potamon 种群状况，它们将被视为独立的管理单位。