Abstract. The majority of Australian Spinicaudata Linder, 1945 inhabit the (semi)arid deserts of Australia’s lowlands. However, several closely related species of Paralimnadia Sars, 1896 inhabit small temporary habitats throughout the Great Dividing Range in eastern Australia. By combining analyses of mitochondrial cytochrome c oxidase subunit I (COI) with double-digest restriction-site associated DNA (ddRAD) data, we studied the species diversity and genetic diversity of this group of mountain-dwelling branchiopods. Levels of genetic differentiation in COI are relatively low between putative species (mostly between 1.5 and 6.7%), complicating COI-based species delimitation. Depending on the applied threshold, three to six species are inferred in the studied area, with most putative species being geographically restricted. Particularly notable are the high levels of population differentiation indicated by ddRAD analyses between nearby populations within putative species. This suggests that gene flow is limited, even between populations separated only by a few kilometres. This may lead to fast population differentiation, which in turn might drive speciation. Our data suggest that the species diversity of Paralimnadia in the Great Dividing Range is much higher than currently appreciated.

中文翻译：

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澳大利亚东部山地蛤虾的遗传分化，Paralimnadia（甲壳纲：Branchiopoda：Spinicaudata）

摘要。1945 年的大多数澳大利亚棘尾纲动物栖息在澳大利亚低地的（半）干旱沙漠中。然而，Paralimnadia Sars, 1896 的几个密切相关的物种栖息在澳大利亚东部大分水岭的小型临时栖息地。通过将线粒体细胞色素 c 氧化酶亚基 I (COI) 与双酶切限制性位点相关 DNA (ddRAD) 数据的分析相结合，我们研究了这组山栖鳃足类动物的物种多样性和遗传多样性。假定物种之间的 COI 遗传分化水平相对较低（主要在 1.5% 和 6.7% 之间），使基于 COI 的物种定界复杂化。根据应用的阈值，在研究区域推断出 3 到 6 个物种，大多数假定的物种在地理上受到限制。特别值得注意的是推定物种内附近种群之间的 ddRAD 分析表明高水平的种群分化。这表明基因流动是有限的，即使在相距仅几公里的种群之间也是如此。这可能会导致快速的种群分化，进而推动物种形成。我们的数据表明，大分水岭中 Paralimnadia 的物种多样性远高于目前的认识。