Related Data for: Partial bleaching and survival responses in the outer mantle of the giant clam Tridacna squamosa exposed to temperature stress

In this study, giant clams (Tridacna squamosa) were kept at 26 °C (control) or exposed to 31 °C for a maximum of 57 days to evaluate whether symbionts and host cells in the colorful outer mantle could acclimate to temperature stress in accordance with the oxidative stress theory of bleaching. Elevated temperature led to partial bleaching of the outer mantle, leaving behind ∼ 36% of the symbiont population that appeared acclimated.

Such partial loss of symbionts could be a survival strategy to limit excessive reactive oxygen species (ROS) generation by reducing the total symbiont population. The surviving symbionts had a reduced carbon-fixing capacity with substantially less form II ribulose-1,5-bisphosphate carboxylase/oxygenase protein. However, chlorophyll and peridinin contents increased ∼ twofold in these symbionts, presumably forming more peridinin–chlorophyll-a–protein that could act as an antioxidant inside the plastids.