Study on the behavioral and metabolic response mechanisms of Peronia verruculata to marine heatwaves.

Intertidal organisms face severe thermal stress due to global warming and frequent marine heatwaves. Thus, this study focused to investigate metabolic characteristics of the intertidal marine mollusk Peronia verruculata under different intensities of simulated marine heatwave stress (Normal Temperature, NT: 26 °C; High Temperature, HT: 30 °C; and Extreme High Temperature, EHT: 34 °C) for 72 h based on behavioral observations, body energy reserves, and differential metabolic markers. The results showed that the survival rate, cumulative movement distance, movement duration, and feeding duration in the EHT group were significantly lower (P < 0.05) compared to the NT group. Cosinor analysis revealed no significant (P > 0.05) rhythmicity in the cumulative movement distance, movement duration, or feeding duration between day and night across all groups. At the end of the experiment, a significant difference in total energy reserves and malondialdehyde content was observed among all groups. The total energy reserves followed the order NT > HT > EHT, while malondialdehyde content followed the order NT < HT < EHT (P < 0.05). LC-MS screening identified differential metabolic markers such as PC (20:4(5Z,8Z,11Z,14Z)/14:0), CDP-choline, GDP-mannose, fumaric acid, anthranilic acid (Vitamin L1), and kynurenic acid. Several differential metabolites were significantly enriched in eight signaling pathways, including tryptophan metabolism, glycerophospholipid metabolism, and oxidative phosphorylation. Furthermore, the targeted metabolomics studies found that, compared to the NT group, the contents of 11 amino acids were significantly increased (P < 0.05), and the contents of 8 amino acids were significantly decreased (P < 0.05) in the HT and EHT groups. These observations revealed the multi-level adaptation strategies of Peronia verruculata, involving behavioral shifts and amino acid metabolism, in response to marine heatwaves, providing a theoretical basis for understanding the ecological adaptation mechanisms of intertidal organisms under climate change.