Rainbow trout (Oncorhynchus mykiss) farming is one of the major aquacultures in Turkey. Some conditions in fish farming can induce oxidative stress leading to the deterioration in properties such as appearance/color, texture, and flavor in fish meat. This situation may cause the consumer not to prefer edible fish. Although there are some studies on the impacts of light intensity on fish welfare, the changes in the antioxidant enzyme activities have not been elucidated. In the current study, it was intended to examine in rainbow trout how cultivating under different wavelengths affects the antioxidant enzymes and acetylcholine esterase (AChE) activity, because its activity is associated with oxidative stress, and also the determination of which light is suitable for fish welfare was aimed. Rainbow trout larvae were grown under four lights with different wavelengths: natural sunlight and incandescent long-wave (red light), medium-wave (green light), and short-wave (blue light) LED light. The experiment lasted for 64 days. Biochemical assays were carried on in the brain, gill, and liver of rainbow trout. Antioxidant enzymes and AChE activity, which play an important role in the central nervous system, were assayed. In gill tissues, superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glucose 6 phosphate dehydrogenase (G6PD), glutathione reductase (GR), glutathione S-transferase (GST), and AChE activities increased under all three light wavelengths. In the liver, while activities of antioxidant enzymes and AChE decreased in red light, all of them increased in blue and green light. In the brain, GPx, GST, G6PD, and SOD activities were reduced but AChE activity did not alter under all three light sources. In conclusion, light sources with different spectral structures caused important changes in the activities of antioxidant enzymes in rainbow trout. On this basis, it may be thought that this may be a response to the changing redox status of a cell. Based on our results, blue light sources may be suggested for fish welfare in rainbow trout culture, and providing fish welfare by changing light sources can be easy and cheap in fish farming.

虹鳟鱼（Oncorhynchus mykiss）农业是土耳其主要的水产养殖之一。养鱼业中的某些条件会引起氧化应激，从而导致鱼肉的外观/颜色，质地和风味等特性下降。这种情况可能导致消费者不喜欢食用鱼。尽管对光强度对鱼类福利的影响进行了一些研究，但尚未阐明抗氧化酶活性的变化。在当前的研究中，旨在研究虹鳟鱼在不同波长下的培养如何影响抗氧化酶和乙酰​​胆碱酯酶（AChE）的活性，因为其活性与氧化应激相关，并且还确定哪种光适合鱼类福利是针对的。虹鳟鱼幼虫在四种不同波长的光下生长：自然光和白炽灯的长波（红光），中波（绿光）和短波（蓝光）LED灯。实验持续了64天。在虹鳟鱼的脑，腮和肝中进行生化分析。分析了在中枢神经系统中起重要作用的抗氧化酶和AChE活性。在所有三种情况下，g组织中的超氧化物歧化酶（SOD），过氧化氢酶（CAT），谷胱甘肽过氧化物酶（GPx），葡萄糖6磷酸脱氢酶（G6PD），谷胱甘肽还原酶（GR），谷胱甘肽S-转移酶（GST）和AChE活性均升高光的波长。在肝脏中，虽然红光下抗氧化酶和AChE的活性下降，但蓝光和绿光下它们均增加。在大脑中，GPx，GST，G6PD，SOD活性降低，但在所有三种光源下AChE活性均未改变。总之，具有不同光谱结构的光源在虹鳟鱼中引起抗氧化酶活性的重要变化。在此基础上，可以认为这可能是对电池氧化还原状态变化的响应。根据我们的结果，在虹鳟鱼养殖中可以建议使用蓝色光源来保护鱼类，通过改变光源来提供鱼类福利在鱼类养殖中既容易又便宜。