Data from: Does mating behaviour affect connectivity in marine fishes? Comparative population genetics of two protogynous groupers (Family Serranidae)

Pelagic larval duration (PLD) has been hypothesized to be the primary predictor of connectivity in marine fishes; however, few studies have examined the effects that adult reproductive behaviour may have on realized dispersal. We assessed gene flow (connectivity) by documenting variation in microsatellites and mitochondrial DNA sequences in two protogynous species of groupers, the aggregate spawning red hind, Epinephelus guttatus, and the single-male, harem-spawning coney, Cephalopholis fulva, to ask if reproductive strategy affects connectivity. Samples of both species were obtained from waters off three islands (Puerto Rico, St. Thomas, and St. Croix) in the Caribbean Sea. Despite the notion that aggregate spawning of red hind may facilitate larval retention, stronger signals of population structure were detected in the harem-spawning coney. Heterogeneity and/or inferred barriers, based on microsatellites, involved St. Croix (red hind and coney) and the west coast of Puerto Rico (coney). Heterogeneity and/or inferred barriers, based on mitochondrial DNA, involved St. Croix (coney only). Genetic divergence in both species was stronger for microsatellites than for mitochondrial DNA, suggesting sex-biased dispersal in both species. Long-term migration rates, based on microsatellites, indicated asymmetric gene flow for both species in the same direction as mean surface currents in the region. Red hind had higher levels of variation in microsatellites and lower levels of variation in mitochondrial DNA. Long-term effective size and effective number of breeders were greater for red hind; estimates of θf a proxy for long-term effective female size, were the same in both species. Patterns of gene flow in both species appear to stem in part from shared aspects of larval and adult biology, local bathymetry, and surface current patterns. Differences in connectivity and levels of genetic variation between the species, however, likely stem from differences in behaviour related to reproductive strategy.浮游幼体期（Pelagic larval duration, PLD）被假设为海洋鱼类种群连通性的核心预测因子，但鲜有研究探讨成体繁殖行为对实际扩散过程的影响。本研究通过分析两种雌先熟（protogynous）石斑鱼（groupers）的微卫星（microsatellites）与线粒体DNA（mitochondrial DNA）序列变异，评估了与种群连通性相关的基因流（gene flow），所涉物种分别为集群产卵的红斑石斑（Epinephelus guttatus）以及单雄后宫式产卵的花斑鮨（Cephalopholis fulva），旨在探究繁殖策略是否会对种群连通性产生影响。两种鱼类的样本均采集自加勒比海（Caribbean Sea）三座岛屿周边海域：波多黎各、圣托马斯岛与圣克罗伊岛。尽管有观点认为红斑石斑的集群产卵行为可能促进幼体滞留，但在后宫式产卵的花斑鮨中检测到了更强的种群结构（population structure）信号。基于微卫星数据得到的遗传异质性与/或推断的扩散障碍，涉及圣克罗伊岛（红斑石斑与花斑鮨均受影响）以及波多黎各西海岸（仅花斑鮨受影响）；基于线粒体DNA数据的遗传异质性与/或推断的扩散障碍，则仅涉及圣克罗伊岛（仅花斑鮨受影响）。两种石斑鱼的微卫星遗传分化程度均显著高于线粒体DNA，暗示二者均存在性别偏向扩散（sex-biased dispersal）。基于微卫星数据估算的长期迁移率（long-term migration rates）显示，两种石斑鱼的基因流均呈现不对称性，且迁移方向与该区域的平均表层海流（surface currents）方向一致。红斑石斑的微卫星遗传变异水平更高，而线粒体DNA遗传变异水平则更低。红斑石斑的长期有效种群大小（effective size）与有效繁殖个体数（effective number of breeders）均高于花斑鮨；而作为长期有效雌性种群大小替代指标的θ_f，在两种鱼类中的估算值一致。两种石斑鱼的基因流格局，似乎部分源于幼体与成体生物学特征的共性、局地水深地形以及表层海流模式，但二者在种群连通性与遗传变异水平上的差异，则大概率源于繁殖策略相关的行为差异。