Ultraviolet B radiation (UVB) has been recognized as a significant stressor for marine vertebrates, mainly in fish confined to aquaculture cages. However, the information regarding exposure of confined fish to underwater UVB levels is still scarce, particularly in oligotrophic and highly transparent waters, mostly due to deeper UVB penetration.</p><p>This study aimed to investigate the effects of UVB exposure on the global gene expression profiles of S. aurata through transcriptome analysis (RNAseq, Illumina, HiSeq 4000). S. aurata juveniles were exposed for 43 days to two experimental groups: 1) UVB (daily dose, 6 kJ m-2 representing levels between 5 and 7 m depth) 2) Unirradiated treatment, used as a control. Functional annotation analysis revealed that genes related to the immune system and inflammatory response, cell cycle regulation, proteasome, proteolysis, and oxidative stress response might be involved in response to the UVB exposure. This study provides noteworthy insights into the molecular changes in fish exposed to UVB.