To examine the growth and immune response of steelhead trout (Oncorhynchus mykiss) under conditions of differing light color, we investigated the effects of different red and blue light color combinations on plasma non-specific immunity, hepatic antioxidant capacity, and GH/IGF-1 axis gene expression in juvenile steelhead trout (initial weight: 34.67 ± 2.69 g). The 16-week trial was set up with six treatments in which light color varied at a constant light intensity of 150 lx: 12 h white light + 12 h dark (12 W), 12 h blue light + 12 h dark (12B), 12 h red light + 12 h dark (12 R), 1.5 h blue light + 9 h red light + 1.5 h blue light + 12 h dark (3B9R), 3 h blue light + 6 h red light + 3 h blue light + 12 h dark (6B6R), total 12 h of blue and red light + 12 h dark (T12BR). The results revealed that the 12B and 3B9R light environments significantly enhanced plasma immunoglobulin M levels in steelhead trout, and that the 3B9R light environment also promoted significant increases in the gene expression of hepatic growth hormone receptor, insulin-like growth factor 1, and insulin-like growth factor-binding protein. The 3B9R light environment was also found enhance the antioxidant capacity of trout by increasing hepatic superoxide dismutase, catalase, and glutathione peroxidase activities. In contrast, trout exposed to the 6B6R light environment showed significant reductions in growth and immune performance, and there were similar reductions in hepatic antioxidant capacity. Furthermore, fish exposed to the 12R light environment were found to be characterized by elevated levels of lipid peroxidation and malondialdehyde, which are indicative of hepatic stress. In addition, we observed that in response to light variation, there were elevations in the activities of glutamic oxaloacetic transaminase and lactic dehydrogenase in the plasma of steelhead trout, thereby indicating an inhibition of cardiomyocyte function. In summary, our findings indicate that a 3B9R light environment simulates the blue-red-blue daily rhythm of light color variation in natural underwater environments, which is beneficial with respect to enhancing the growth and immunity of steelhead trout, and could accordingly be used to provide suitable light conditions in commercial trout production. However, sudden changes in light color should be avoided in the aquaculture of trout.

检测虹鳟 ( Oncorhynchus mykiss ) 的生长和免疫反应) 在不同光色条件下，我们研究了不同红蓝光颜色组合对虹鳟幼鱼血浆非特异性免疫、肝脏抗氧化能力和GH/IGF-1轴基因表达的影响（初始重量：34.67 ± 2.69 克）。为期 16 周的试验设置了六种处理，其中光色在 150 lx 的恒定光强度下变化：12 小时白光 + 12 小时暗 (12 W)、12 小时蓝光 + 12 小时暗 (12B)、 12 小时红光 + 12 小时暗 (12 R), 1.5 小时蓝光 + 9 小时红光 + 1.5 小时蓝光 + 12 小时暗 (3B9R), 3 小时蓝光 + 6 小时红光 + 3 小时蓝光 + 12 小时黑暗 (6B6R)，总共 12 小时蓝光和红光 + 12 小时黑暗 (T12BR)。结果表明，12B 和 3B9R 光环境显着提高了虹鳟的血浆免疫球蛋白 M 水平，并且 3B9R 光环境还促进肝脏生长激素受体、胰岛素样生长因子 1 和胰岛素样生长因子结合蛋白的基因表达显着增加。还发现 3B9R 光环境通过增加肝脏超氧化物歧化酶、过氧化氢酶和谷胱甘肽过氧化物酶的活性来增强鳟鱼的抗氧化能力。相比之下，暴露于 6B6R 光环境的鳟鱼的生长和免疫性能显着下降，肝脏抗氧化能力也有类似的下降。此外，发现暴露于 12R 光环境的鱼的特征是脂质过氧化和丙二醛水平升高，这表明肝脏应激。此外，我们观察到响应光线变化，虹鳟血浆中谷氨酸草酰乙酸转氨酶和乳酸脱氢酶的活性升高，表明心肌细胞功能受到抑制。综上所述，我们的研究结果表明，3B9R光环境模拟了自然水下环境中光色变化的蓝-红-蓝每日节奏，有利于增强虹鳟的生长和免疫力，因此可用于为商业鳟鱼生产提供合适的光照条件。但是，养殖鳟鱼时应避免光色突然变化。我们的研究结果表明，3B9R光环境模拟了自然水下环境中光色变化的蓝-红-蓝每日节奏，有利于增强虹鳟的生长和免疫力，因此可用于提供合适的光照商业鳟鱼生产的条件。但是，养殖鳟鱼时应避免光色突然变化。我们的研究结果表明，3B9R光环境模拟了自然水下环境中光色变化的蓝-红-蓝每日节奏，有利于增强虹鳟的生长和免疫力，因此可用于提供合适的光照商业鳟鱼生产的条件。但是，养殖鳟鱼时应避免光色突然变化。