Present study was conducted to accurately evaluate the optimal dietary lipid level in golden pompano (Trachinotus ovatus) diets combining phenotypic responses and transcriptomics analysis. Fish with initial body weight 27.65 g ± 0.17 g were fed diets with six lipid levels (9.13%, 10.59%, 12.12%, 14.98%, 16.25%, 19.26%), respectively. Results showed that dietary lipid levels significantly altered the weight gain rate, specific growth rate protein efficiency ratio and reached the maximum when fish fed diet with 12.12% lipid. Proximate composition analysis indicated that body nutrients content were significantly improved by dietary lipid levels. Moreover, total glucose, triglycerides and high-density lipoprotein were also elevated by dietary lipid level. Transcriptomic analysis suggested that muscle growth regulation, hormone response, nutrient metabolism and immune response were more sensitive to dietary lipid levels. Further analyzed mechanisms, data demonstrated that dietary lipid levels could through nutrient sensing signaling pathways to regulate lipid metabolism. Meanwhile, Diet 3 (lipid level: 12.12%) had lower level mRNA expression of the key regulators in immune responses and antioxidant defense. Either too lower or too higher lipid in diet could trigger oxidative stress and immune responses. In conclusion, according to broken-line regression on WGR and SGR, the optimal lipid level for golden pompano were 11.28% and 11.20%, respectively. Present study provided the optimal requirement of dietary lipid level based on a comprehensive method.

本研究旨在准确评估金鲳鱼 ( Trachinotus ovatus ) 的最佳膳食脂质水平) 结合表型反应和转录组学分析的饮食。初始体重为 27.65 g ± 0.17 g 的鱼分别饲喂六种脂质水平（9.13%、10.59%、12.12%、14.98%、16.25%、19.26%）的饲料。结果表明，日粮脂质水平显着改变了鱼的增重率、比生长率蛋白质效率比，并在鱼饲喂12.12%脂质时达到最大值。近似成分分析表明，膳食脂质水平显着提高了身体营养素含量。此外，总葡萄糖、甘油三酯和高密度脂蛋白也因膳食脂质水平而升高。转录组学分析表明，肌肉生长调节、激素反应、营养代谢和免疫反应对膳食脂质水平更敏感。进一步分析机制，数据表明，膳食脂质水平可以通过营养传感信号通路来调节脂质代谢。同时，饮食 3（脂质水平：12.12%）在免疫反应和抗氧化防御中的关键调节因子的 mRNA 表达水平较低。饮食中脂质过低或过高都会引发氧化应激和免疫反应。综上所述，根据WGR和SGR的折线回归，金鲳的最佳血脂水平分别为11.28%和11.20%。本研究基于综合方法提供了膳食脂质水平的最佳要求。饮食中脂质过低或过高都会引发氧化应激和免疫反应。综上所述，根据WGR和SGR的折线回归，金鲳的最佳血脂水平分别为11.28%和11.20%。本研究基于综合方法提供了膳食脂质水平的最佳要求。饮食中脂质过低或过高都会引发氧化应激和免疫反应。综上所述，根据WGR和SGR的折线回归，金鲳的最佳血脂水平分别为11.28%和11.20%。本研究基于综合方法提供了膳食脂质水平的最佳要求。