One of the many environmental factors affecting the health of both farmed and wild fish is exposure to solar ultraviolet radiation (UVR). These rays penetrate to biologically relevant depths in natural waters and cause changes ranging from embryo malfunction to the production of heat‐shock proteins. As suppression of cell‐mediated immunity has been shown to follow irradiation of mammals, the possibility of UVR‐induced modulation in immune responses in fish is considered in this review. It is suggested that, after adsorption of UV photons by surface chromophores, dendritic‐like cells may be activated by immune mediators, leading to the generation of T‐ and B‐cell subsets with down‐regulatory activity. A limited number of studies involving infection of irradiated fish with bacteria, nematodes and protozoa have demonstrated an increased microbial load and lack of clearance, with associated changes in a variety of immune parameters. These preliminary results indicate that exposure of fish to solar UVR leads to less effective control of infections. Strategies evolved by fish to avoid overexposure to UVR include photoenzymatic repair, nucleotide excision repair, pigments, mycosporine‐like amino acids and habitat selection. The welfare of farmed fish is of concern currently. The detrimental effects of excessive sun exposure on the health of fish require recognition, and procedures put in place to minimize such consequences.

中文翻译：

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太阳紫外线辐射对鱼类的影响：免疫调节和光防护策略

影响养殖鱼类和野生鱼类健康的许多环境因素之一是暴露于太阳紫外线辐射（UVR）。这些射线穿透到自然水中的生物学相关深度，并引起从胚胎故障到热休克蛋白产生的变化。由于已经证明在哺乳动物照射后会抑制细胞介导的免疫，因此本评价考虑了UVR诱导的鱼类免疫反应调节的可能性。建议在表面生色团吸附紫外线光子后，树突状细胞可能被免疫介质激活，导致产生具有下调活性的T细胞和B细胞亚群。有限的研究涉及用细菌感染辐照鱼，线虫和原生动物已显示出增加的微生物负荷和缺乏清除率，以及各种免疫参数的相关变化。这些初步结果表明，将鱼暴露在太阳紫外线辐射下会导致对感染的有效控制较差。鱼类为了避免过度暴露于紫外线而采取的策略包括光酶修复，核苷酸切除修复，色素，霉菌素样氨基酸和栖息地选择。目前，养殖鱼的福利受到关注。过度暴露于阳光对鱼类健康的有害影响需要得到认可，并采取适当的措施以尽量减少此类后果。鱼类为了避免过度暴露于紫外线而采取的策略包括光酶修复，核苷酸切除修复，色素，霉菌素样氨基酸和栖息地选择。目前，养殖鱼的福利受到关注。过度暴露于阳光对鱼类健康的有害影响需要得到认可，并采取适当的措施以尽量减少此类后果。鱼类为了避免过度暴露于紫外线而采取的策略包括光酶修复，核苷酸切除修复，色素，霉菌素样氨基酸和栖息地选择。目前，养殖鱼的福利受到关注。过度暴露于阳光对鱼类健康的有害影响需要得到认可，并采取适当的措施以尽量减少此类后果。