Heat-evolved algal symbionts enhance thermotolerance of adult corals without growth trade-off

Heat-evolved microalgal symbionts of the generalist species, Cladocopium proliferum (strain SS8), were exposed to elevated temperature (31°C) for ~10 years and were introduced into four genotypes of chemically bleached adult fragments of the scleractinian coral, Galaxea fascicularis. Two of the four coral genotypes acquired SS8 and the new symbionts persisted for the 5 months of the experiment and enhanced adult coral thermotolerance, compared with corals that were inoculated with the wild-type C. proliferum strain. All raw data and R codes for statistical analysis are available on https://doi.org/10.5281/zenodo.8336616. Details of each file are provided in Table S15. Metabolite annotations on MetaSpace are available at https://metaspace2020.eu/ (project name: heat-evolved algal symbionts enhance thermotolerance of adult corals without growth trade-off). Raw sequences of the ITS2 Symbiodiniaceae data sets are available in GenBank (project Accession nos.: PRJNA983409; SRR24910332-SRR24910491).