Data from: Unexpected cryptic species diversity in the widespread coral Seriatopora hystrix masks spatial-genetic patterns of connectivity

Mounting evidence of cryptic species in a wide range of taxa highlights the need for careful analyses of population genetic data sets to unravel within-species diversity from potential interspecies relationships. Here, we use microsatellite loci and hierarchical clustering analysis to investigate cryptic diversity in sympatric and allopatric (separated by 450 km) populations of the widespread coral Seriatopora hystrix on the Great Barrier Reef. Structure analyses delimited unique genetic clusters that were confirmed by phylogenetic and extensive population-level analyses. Each of four sympatric yet distinct genetic clusters detected within S. hystrix demonstrated greater genetic cohesion across regional scales than between genetic clusters within regions (<10 km). Moreover, the magnitude of genetic differentiation between different clusters (>0.620 G”ST) was similar to the difference between S. hystrix clusters and the congener S. caliendrum (mean G”ST 0.720). Multiple lines of evidence, including differences in habitat specificity, mitochondrial identity, Symbiodinium associations and morphology, corroborate the nuclear genetic evidence that these distinct clusters constitute different species. Hierarchical clustering analysis combined with more traditional population genetic methods provides a powerful approach for delimiting species and should be regularly applied to ensure that ecological and evolutionary patterns interpreted for single species are not confounded by the presence of cryptic species.越来越多的证据表明，多个类群中存在隐存物种（cryptic species），这凸显了对种群遗传数据集开展严谨分析的必要性——唯有如此，才能从潜在的种间关系中厘清物种内部的多样性。本研究以大堡礁广布造礁物种多刺尖枝轴孔珊瑚（Seriatopora hystrix）的同域及异域（地理间隔450 km）种群为研究对象，利用微卫星位点（microsatellite loci）与层级聚类分析（hierarchical clustering analysis）探究其隐存多样性。STRUCTURE群体结构分析界定出了独特的遗传簇，这一结果得到了系统发育分析与大规模种群水平分析的验证。在多刺尖枝轴孔珊瑚中检出的4个同域却独立的遗传簇，其跨区域尺度的遗传一致性均高于区域内（<10 km）不同遗传簇间的遗传一致性。此外，不同遗传簇间的遗传分化程度（>0.620 G”ST）与多刺尖枝轴孔珊瑚的遗传簇和同属物种卡氏尖枝轴孔珊瑚（S. caliendrum）间的遗传分化程度（平均G”ST为0.720）相当。多项证据——包括生境特异性差异、线粒体特征差异、虫黄藻（Symbiodinium）共生关系差异以及形态学差异——均佐证了核遗传证据，即这些独立的遗传簇实为不同的物种。层级聚类分析结合更为经典的种群遗传学方法，为物种界定提供了一种高效可靠的手段，该方法应被常规应用，以确保针对单一物种阐释的生态学与进化模式不会因隐存物种的存在而被混淆。