Knowledge of population structure and genetic diversity within and between wild and farmed populations of gilthead sea bream (Sparus aurata) and European seabass (Dicentrarchus labrax) is important to achieve sustainable aquaculture production of these species and to assess the risk of genetic impacts of fish escaped from farms. Previous population genetic studies on these species have been based on a limited number of genetic markers and samples. In this study, these features were assessed using samples from 24 seabream and 25 seabass populations distributed throughout the Mediterranean Sea, and 3 wild seabream Atlantic populations. Samples were genotyped with a newly developed combined species SNP array that includes ~60K SNPs. Data from sequencing pools of individual DNA from the same populations were also used. Different approaches were employed for identifying the extent of population stratification within species. The effective population size (a parameter inversely related to the rate at which genetic variability is lost) was estimated for each population based on linkage disequilibrium. Population structure results revealed a clear differentiation between wild and farmed populations in both species. Wild populations showed a low degree of differentiation, particularly in seabream. Despite this, a slight differentiation was observed between Atlantic and Mediterranean seabream populations and between western and eastern Mediterranean seabass populations. However, farmed populations were quite heterogeneous and showed a high degree of differentiation. Some farmed populations of both species showed a genetic makeup similar to that found in wild populations. In general, the effective population size was large (> 1000) for wild and small (< 100) for farmed populations of both species. About 40% of the seabream and 80% of the seabass farmed populations had estimates of effective population size smaller than 50 highlighting the need of applying measures to control the rate at which genetic variability is lost.

了解金头鲷 ( Sparus aurata ) 和欧洲海鲈 ( Dicentrarchus labrax ) 野生和养殖种群内部和之间的种群结构和遗传多样性) 对于实现这些物种的可持续水产养殖生产和评估从养殖场逃逸的鱼类的遗传影响风险非常重要。以前对这些物种的种群遗传研究是基于有限数量的遗传标记和样本。在这项研究中，使用分布在整个地中海的 24 个海鲷和 25 个海鲈种群以及 3 个大西洋野生海鲷种群的样本评估了这些特征。使用新开发的组合物种 SNP 阵列对样品进行基因分型，该阵列包括约 60K SNP。还使用了来自同一群体的个体 DNA 测序库的数据。采用不同的方法来确定物种内种群分层的程度。基于连锁不平衡估计每个种群的有效种群大小（与遗传变异性丢失率成反比的参数）。种群结构结果显示，这两个物种的野生种群和养殖种群之间存在明显差异。野生种群表现出低程度的分化，特别是在鲷鱼中。尽管如此，在大西洋和地中海海鲷种群之间以及在地中海西部和东部海鲈种群之间观察到了轻微的差异。然而，养殖种群非常异质并且表现出高度分化。这两个物种的一些养殖种群显示出与野生种群相似的遗传构成。一般来说，对于野生和小型（< 100) 用于这两个物种的养殖种群。大约 40% 的鲷鱼和 80% 的鲈鱼养殖种群估计有效种群规模小于 50，这突出表明需要采取措施控制遗传变异性丧失的速度。