Genetic improvement of feed efficiency is key to improve the economic and environmental sustainability of fish farming. However, it requires individual phenotypes of feed efficiency, which are difficult if not impossible to obtain when fish are reared in tanks or cages. Here, we applied and validated on gilthead sea bream a method to evaluate individual feed efficiency based on individual rearing of fish in aquariums under restricted feeding. We collected individual phenotypes of feed efficiency in aquariums on 538 sea bream (average weight = 54.50 g). Based on these individual phenotypes, fish (average weight = 174.6 g) were reared in groups of divergent phenotypes (high or low feed efficiency), validating that individual feed efficiency had an impact on group feed efficiency at a later stage. All 538 fish, their parents as well as 794 sibs reared in cages in a production environment, were genotyped on a 57k SNP array to estimate genomic heritability and correlations between traits. We showed that feed efficiency was heritable but did not find significant associated QTLs. We also showed that feed efficiency was negatively genetically correlated to viscera yield, indicating that the most efficient fish had less viscera than the least efficient ones. Altogether, these results support that measuring individual feed efficiency in aquariums under restricted feeding may be used as a reliable phenotyping method to genetically improve feed efficiency, despite the bias intrinsically linked to individual rearing.

饲料效率的遗传改良是提高养鱼业经济和环境可持续性的关键。然而，它需要单独的饲料效率表型，当鱼在水箱或网箱中饲养时，即使不是不可能，也很难获得。在这里，我们在金头鲷上应用并验证了一种基于限制喂养条件下在水族馆中个体饲养鱼类来评估个体饲料效率的方法。我们在 538 条鲷鱼（平均体重 = 54.50 g）上收集了水族箱中饲料效率的个体表型。基于这些个体表型，鱼（平均体重 = 174.6 g）在不同表型（高或低饲料效率）组中饲养，证实个体饲料效率在后期对组饲料效率有影响。所有 538 条鱼，他们的父母以及在生产环境中笼养的 794 名同胞在 57k SNP 阵列上进行基因分型，以估计基因组遗传力和性状之间的相关性。我们发现饲料效率是可遗传的，但没有发现显着相关的 QTL。我们还表明，饲料效率与内脏产量呈负相关，这表明效率最高的鱼比效率最低的鱼的内脏更少。总而言之，这些结果支持在限制饲养条件下测量水族箱中的个体饲料效率可用作一种可靠的表型分析方法，以从遗传上提高饲料效率，尽管存在与个体饲养内在相关的偏差。我们发现饲料效率是可遗传的，但没有发现显着相关的 QTL。我们还表明，饲料效率与内脏产量呈负相关，这表明效率最高的鱼比效率最低的鱼的内脏更少。总而言之，这些结果支持在限制饲养条件下测量水族箱中的个体饲料效率可用作一种可靠的表型分析方法，以从遗传上提高饲料效率，尽管存在与个体饲养内在相关的偏差。我们发现饲料效率是可遗传的，但没有发现显着相关的 QTL。我们还表明，饲料效率与内脏产量呈负相关，这表明效率最高的鱼比效率最低的鱼的内脏更少。总而言之，这些结果支持在限制饲养条件下测量水族箱中的个体饲料效率可用作一种可靠的表型分析方法，以从遗传上提高饲料效率，尽管存在与个体饲养内在相关的偏差。