1. The dusky grouper Epinephelus marginatus is a large epinephelid species that occurs in the eastern and south-western Atlantic and western Indian Oceans. Late maturity, protogynous hermaphroditism, site fidelity, and overfishing have all contributed to its demographic decline.
2. Connectivity and demography within a broad sampling of dusky grouper populations throughout its distribution were assessed. To do so, genetic variation at 11 polymorphic microsatellite loci and a partial sequence of the mitochondrial control region (mtCR) were evaluated.
3. Two major mtCR lineages with a sequence divergence of 1.6% were found. The magnitude of genetic differentiation for mtCR among north and south Atlantic and Indian Ocean populations was high, with Φ_ST = 0.528.
4. D_EST and results of discriminant analysis of principal component revealed significant microsatellite genetic differentiation between all collection areas. Significant pairwise D_EST showed moderate (0.084) to very great (0.603) differentiation. The effective population size was low for all localities, ranging between 25 (Azores Archipelago) and 311 (Rio Grande do Sul). The overall effective population size was estimated as 299 (confidence interval = 215–412), and there was no evidence of strong or recent bottleneck effects.
5. Local and regional genetic structuring among dusky grouper populations is the consequence of the species' site fidelity, distribution across multiple oceanographic boundaries, and probably also of sequential hermaphroditism that contributes to the intensity of random genetic drift.
6. The spatial pattern of genetic structuring of dusky groupers is such that fisheries management and conservation of population genetic integrity will have to be pursued at the local and regional scales.

中文翻译：

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连续雌雄同体、暗色石斑鱼 (Epinephelus marginatus) 的全球种群遗传结构

1. 暗色石斑鱼Epinephelus marginatus是一种大型的石斑鱼，生活在大西洋东部和西南部以及印度洋西部。晚熟、雌雄同体、场地保真和过度捕捞都导致其人口下降。
2. 评估了整个分布范围内的暗色石斑鱼种群的广泛抽样中的连通性和人口统计学。为此，评估了 11 个多态性微卫星位点的遗传变异和线粒体控制区 (mtCR) 的部分序列。
3. 发现了两个主要的 mtCR 谱系，序列差异为 1.6%。北大西洋和南大西洋以及印度洋种群中 mtCR 的遗传分化程度很高，Φ _ST  = 0.528。
4. D _EST和主成分判别分析结果显示所有采集区域之间存在显着的微卫星遗传差异。显着的成对D _EST显示出中等 (0.084) 到非常大 (0.603) 的分化。所有地区的有效人口规模都很低，范围在 25（亚速尔群岛）和 311（南里奥格兰德）之间。总体有效人口规模估计为 299（置信区间 = 215-412），并且没有证据表明存在强烈或近期的瓶颈效应。
5. 暗色石斑鱼种群中的局部和区域遗传结构是该物种的位置保真度、跨多个海洋边界分布的结果，也可能是导致随机遗传漂移强度的连续雌雄同体的结果。
6. 暗色石斑鱼遗传结构的空间格局使得渔业管理和种群遗传完整性保护必须在当地和区域范围内进行。