Exposure to natural ultraviolet B radiation levels has adverse effects on growth, behavior, physiology, and innate immune response in juvenile European seabass (Dicentrarchus labrax)

Solar ultraviolet B radiation (UVB) has been underestimated as a stressor in fish species that grow confined cages, especially cultured oligotrophic waters receive high levels of UVB. In this context, the present study aims to assess UVB radiation's adverse effects on European seabass (Dicentrarchus labrax), which is Mediterranean and Red Sea. Seabass juveniles were exposed for six weeks four experimental conditions simulated natural underwater conditions: (1) dose - UVB-H, 11.86 kJ m?2 d?1; (2) moderate UVB-M, 6.28 (3) low UVB-L, 2.55 (4) no exposure control. Specimens collected after 3, 15 (short-term), 43 (long-term) days growth, behavior, physiology, immune system investigated. Overall, data showed short- long-term resulted detrimental seabass, some these cumulative dose-dependent. High mortality (around 50%) was observed 3 highest daily (UVB-H). No significant or control throughout experiment. Reduction growth changes animal body condition indices evident UVB-M exposure. The swimming activity reduced treatment, most from treatment tried avoid while showing stationary behavior with slow caudal dorsal fins movements. A lack appetite during experiment, total protein, glucose, lactate, cholesterol plasmatic reflected physiological impairment. Furthermore, several humoral parameters suggest an modulation can occur three treatments (UVB-L, UVB-H), different periods (3, 15, days). our provide evidence that, case confinement are sensitive exposure, UV incidence such Hence, seabass' resistance pathogens, survival may be affected by Further research recommended understand how future increases when combined other environmental stressors.