Thermal plasticity of coral reef symbionts is linked to major alterations in their lipidome composition

Coral bleaching caused by ocean warming is leading to worldwide coral decline. The physiological processes underlying this ecological event are still incompletely understood, although previous research has suggested oxidative stress as major player in the impairment of symbiont thylakoid membranes and symbiosis breakdown. Lipids interesting targets investigation, given their susceptibility thermal stresses. Here, an untargeted lipidomic approach was employed examine changes lipidome pigments three reef symbionts (Symbiodiniaceae) after a heat shock vitro experiments. acute induced species-specific compositions both sensitive tolerant symbionts. Heat sensitivity characterized steep steady decline cell densities over time (4 240 h shock). At membrane level, displayed quantitative decrease glycolipids linked polyunsaturated fatty acids, followed enrichment oxidized lipids sphingolipids. Despite showing distinct adaptations, two were preservation shock, particularly glycolipids. This finding suggests action powerful antioxidant systems, preventing escalation concentration under stress. Although limited examination free-living symbionts, our study provides solid baseline for investigation alterations Symbiodiniaceae response Novel potential lipid biomarkers suggested. In particular, lipids—which implicated establishment breakdown—appear attractive further research.