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.越来越多的证据显示，各类群中均存在隐存种（cryptic species），这凸显了对种群遗传数据集开展严谨分析的必要性，以厘清物种内多样性与潜在种间关系的边界。本研究借助微卫星位点（microsatellite loci）与层级聚类分析（hierarchical clustering analysis），针对大堡礁广布造礁珊瑚柱形珊瑚（Seriatopora hystrix）的同域分布种群，以及相隔450公里的异域分布种群的隐存多样性展开探究。Structure分析（Structure）所界定的独特遗传簇，经系统发育分析与大规模种群水平分析验证属实。在S. hystrix中检出的4个同域分布却遗传分化（genetic differentiation）显著的遗传簇，在区域尺度上展现出更高的遗传一致性（genetic cohesion），且该一致性高于区域内（<10公里）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S. hystrix簇及其同属物种S. caliendrum之间的遗传分化（平均G_ST为0.720）相当。多项佐证证据——包括生境特异性、线粒体一致性、虫黄藻（Symbiodinium）共生关联以及形态学特征的差异——均支持核遗传证据的结论：这些独特遗传簇实为不同物种。层级聚类分析结合更为传统的种群遗传学方法，为物种界定提供了高效可靠的研究路径，该方法应得到常规应用，以确保针对单一物种的生态学与进化模式解读，不会因隐存种的存在而出现混淆。