Multi-omics reveals responses to thermal acclimation in the narrow-clawed crayfish (Pontastacus leptodactylus).

The narrow-clawed crayfish (Pontastacus leptodactylus) is a cold-water species with considerable aquaculture potential under climate-warming scenarios; however, its physiological response patterns during acclimation to progressively higher temperatures remain unclear. This study evaluated growth and survival during a 25-day thermal acclimation experiment with five final treatment temperatures (22, 25, 28, 31, and 34 °C), together with endpoint hepatopancreatic biochemical measurements and a transcriptomic and metabolomic comparison of the 22 and 31 °C treatments. Tissues analyses used independent sampling cohorts. The 28 °C group showed the highest relative growth metrics and the lowest apparent feed conversion ratio under the tested regime. Survival in the growth cohort remained at 100% in the 22-28 °C groups and declined to 55.56% and 33.33% in the 31 and 34 °C groups, respectively. Superoxide dismutase and catalase activities peaked in the 31 °C treatment, whereas malondialdehyde was elevated and energy-substrate contents were lower in the higher-temperature treatments. The 34 °C treatment showed lower lysozyme activity and higher malondialdehyde content. The omics comparison identified expression and metabolite-abundance differences associated with redox regulation, immune-related processes, and energy metabolism. These results describe the short-term physiological responses of P. leptodactylus under different thermal acclimation conditions.This research results can provide a theoretical basis for the subsequent temperature adaptation strategies of crayfish in aquaculture.