The aquaculture industry increasingly investigates the use of triploid mussels due to their potential for enhanced growth efficiency. Triploidy induction disrupts at least partially gonadal development, potentially redirecting energy towards somatic growth. However, triploid tolerance to environmental stressors like heatwaves remains unclear. Understanding their response to such events is crucial, as heatwaves are becoming longer and more frequent with climate change. The present study compares the metabolic and metabolomic responses of diploid and triploid Mytilus edulis families to heatwave conditions.
Two mussel families were produced. The first family containing triploids from both chemical (6DMAP) and pressure shock (XP) induction, and the second family including triploids obtained by pressure shock alongside its diploid control. Mussels were exposed for three weeks to two temperature scenarios reflecting control and heatwave conditions experienced at Prince Edward Island mussel farms. Oxygen consumption rates were measured in each group and liquid chromatography-tandem mass spectrometry (LC-MS/MS) was used to analyze metabolite profiles for each temperature scenario. The study focuses on two aspects: (1) comparing the effect of heatwave between diploids vs. pressure-shock triploids (family 1), and (2) comparing this effect between triploids obtained from pressure shock vs. chemical shock treatments (family 2).
No significant mortality was observed in any of the treatments during the exposure period. Respirometry recordings indicate higher oxygen consumption rates under heatwave conditions, without differences between triploids and diploids or pressure and chemical shock treatments. By combining these results with metabolomic analyses, we aim to compare metabolic pathways and energy allocations between groups under thermal stress.