show Abstracthide AbstractRainbow trout (Oncorhynchus mykiss) is highly sensitive to high-temperature stress as an important economic cold-water fish. While previous research has concentrated on the transcriptomic to acute heat stress in rainbow trout, there remains a gap in knowledge regarding the overarching regulatory mechanisms at the translation level. In our research, we utilized a combination of transcriptomic and translatomic analyses to investigate the intricate molecular response mechanisms in the liver of rainbow trout when subjected to heat stress. Through comprehensive multi-omics analysis, we revealed the dynamic translational pattern of rainbow trout liver under heat stress for the first time. Comparative analysis of ribosome analysis data with RNA-seq data showed that the fold changes of gene expression at the transcriptional level were highly correlated (R2 = 0.83) with those at the translational level globally. In total, 2,203 genes exhibited significant alterations exclusively within the translational level. However, the limited overlap in response genes between transcription and translation under heat stress suggests that these two processes may independently modulate the cellular response to thermal challenges. Significant changes in the translation efficiency of 809 genes were observed under heat stress. Further analysis indicated that the translation efficiency of genes were strongly influenced by sequence characteristics such as GC content, coding sequence length and NMFE. Moreover, 3,468 putative uORFs were identified in 2,676 genes, which potentially modulating translation efficiency of mORFs. These findings provide a novel perspective for understanding the physiological adaptations of rainbow trout in response to changes in ambient temperature. Overall design: mRNA expression profiles in the liver of rainbow trout (Oncorhynchus mykiss) at 18? and heat stress(24?) for 8 h