Resistance of an intertidal oyster(Saccostrea mordax)to marine heatwaves and the implication for reef building

• Published in: The Science of the total environment Vol. 928; p. 172474
• Main Authors: Guo, Shuming, Li, Jun, Yang, Xiaogang, Qin, Yanping, Zhao, Yuexin, Wei, Jinkuan, Ma, Haitao, Yu, Ziniu, Zhao, Liqiang, Zhang, Yuehuan
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 10.06.2024
• Subjects: Animals; Coral Reefs; Ecological restoration; Ecosystem; Extreme Heat; Heat resistance; Hot Temperature; Marine heatwaves; Ostreidae - physiology; Saccostrea mordax; Thermotolerance; Transcriptome; Heat resistance; Ecological restoration; Marine heatwaves; Saccostrea mordax; Transcriptome
• ISSN: 0048-9697; 1879-1026
• DOI: 10.1016/j.scitotenv.2024.172474

Marine heatwaves (MHWs) have a significant impact on intertidal bivalves and the ecosystems they sustain, causing the destruction of organisms' original habitats. Saccostrea mordax mainly inhabits the intertidal zone around the equator, exhibiting potential tolerance to high temperatures and maybe a species suitable for habitat restoration. However, an understanding about the tolerance mechanism of S. mordax to high temperatures is unclear. It is also unknown the extent to which S. mordax can tolerate repeated heatwaves of increasing intensity and frequency. Here, we simulated the effects of two scenarios of MHWs and measured the physiological and biochemical responses and gene expression spectrum of S. mordax. The predicted responses varied greatly across heatwaves, and no heatwave had a significant impact on the survival of S. mordax. Specifically, there were no statistically significant changes apparent in the standard metabolic rate and the activities of enzymes of the oyster during repeated heatwaves. S. mordax exposed to high-intensity heatwaves enhanced their standard metabolic rate to fuel essential physiological maintenance and increasing activity of SOD and expression of HSP70/90. These strategies are presumably at the expense of functions related to immunity and growth, as best exemplified by significant depressions in activities of enzymes (NaK, CaMg, T-ATP, and AKP) and expression levels of genes (Rab, eEF-2, HMGR, Rac1, SGK, Rab8, etc.). The performance status of S. mordax tends to improve by implementing a suite of less energy-costly compensatory mechanisms at various levels of biological organization when re-exposed to heatwaves. The adaptive abilities shown by S. mordax indicate that they can play a crucial role in the restoration of oyster reefs in tropical seas. [Display omitted] •Saccostrea mordax mainly inhabits the seas around the equator.•The high survival rate exhibits that they will not succumb to the increasing heatwaves.•The multi-level responses illustrate their acclimation to marine heatwaves.•Their heat tolerance potentially contributes to oyster reef restoration.