Ecol Evol. 2012 Jul;2(7):1605-26. doi: 10.1002/ece3.265.
Temporary water bodies are important freshwater habitats in the arid zone of Australia. They harbor a distinct fauna and provide important feeding and breeding grounds for water birds. This paper assesses, on the basis of haplotype networks, analyses of molecular variation and relaxed molecular clock divergence time estimates, the phylogeographic history, and population structure of four common temporary water species of the Australian endemic clam shrimp taxon Limnadopsis in eastern and central Australia (an area of >1,350,000 km(2)). Mitochondrial cytochrome c oxidase subunit I sequences of 413 individuals and a subset of 63 nuclear internal transcribed spacer 2 sequences were analyzed. Genetic differentiation was observed between populations inhabiting southeastern and central Australia and those inhabiting the northern Lake Eyre Basin and Western Australia. However, over large parts of the study area and across river drainage systems in southeastern and central Australia (the Murray-Darling Basin, Bulloo River, and southern Lake Eyre Basin), no evidence of population subdivision was observed in any of the four Limnadopsis species. This indicates recent gene flow across an area of ∼800,000 km(2). This finding contrasts with patterns observed in other Australian arid zone taxa, particularly freshwater species, whose populations are often structured according to drainage systems. The lack of genetic differentiation within the area in question may be linked to the huge number of highly nomadic water birds that potentially disperse the resting eggs of Limnadopsis among temporary water bodies. Genetically undifferentiated populations on a large geographic scale contrast starkly with findings for many other large branchiopods in other parts of the world, where pronounced genetic structure is often observed even in populations inhabiting pools separated by a few kilometers. Due to its divergent genetic lineages (up to 5.6% uncorrected p-distance) and the relaxed molecular clock divergence time estimates obtained, Limnadopsis parvispinus is assumed to have inhabited the Murray-Darling Basin continuously since the mid-Pliocene (∼4 million years ago). This means that suitable temporary water bodies would have existed in this area throughout the wet-dry cycles of the Pleistocene.
临时水体是澳大利亚干旱区重要的淡水栖息地。它们拥有独特的动物群，为水鸟提供重要的觅食和繁殖场所。本文基于单倍型网络、分子变异分析和松弛分子钟分歧时间估计，评估了澳大利亚特有蛤虾类 Limnadopsis 四个常见临时水物种的系统地理学历史和种群结构，这些物种分布在澳大利亚东部和中部（面积超过 135 万平方千米）。对 413 个个体的线粒体细胞色素 c 氧化酶亚基 I 序列和 63 个核内转录间隔区 2 序列的一个子集进行了分析。观察到栖息在东南和澳大利亚中部的种群与栖息在北艾尔湖流域和西澳大利亚的种群之间存在遗传分化。然而，在研究区域的大部分地区和东南和澳大利亚中部的河流流域系统（墨累-达令流域、布洛洛河和南艾尔湖流域），没有观察到四个 Limnadopsis 物种中的任何一个存在种群细分的证据。这表明在大约 80 万平方千米的区域内有最近的基因流。这一发现与在其他澳大利亚干旱区分类群中观察到的模式形成鲜明对比，特别是在那些种群通常根据流域系统进行结构划分的淡水物种中。在所研究区域内没有遗传分化的现象可能与大量高度游牧的水鸟有关，这些水鸟可能在临时水体之间散布 Limnadopsis 的休眠卵。在大地理尺度上遗传上未分化的种群与世界其他地区许多其他大型鳃足类动物的发现形成鲜明对比，在这些地区，即使是栖息在相隔几公里的池塘中的种群，也经常观察到明显的遗传结构。由于 Limnadopsis parvispinus 具有不同的遗传谱系（未校正的 p 距离高达 5.6%）和获得的松弛分子钟分歧时间估计，因此假定它从中新世中期（约 400 万年前）以来就一直连续栖息在墨累-达令流域。这意味着在整个更新世的干湿循环中，这个地区都有适宜的临时水体。
