Facultative Symbiosis in Stony Corals Reveal Key to Survival

Strategic Insights -

Researchers have made a groundbreaking discovery in the field of coral science, shedding light on the underlying biological mechanisms of facultative symbiosis in thermotolerant Mediterranean coral, Oculina patagonica. In a study published in the esteemed journal Nature, scientists from the Barcelona Institute of Science and Technology revealed that this coral species exhibits a unique dual-feeding strategy, allowing it to survive extended periods of bleaching. The research, which involved genomic and cellular analysis, uncovered key adaptations in host cells that enable Oculina patagonica to thrive in challenging environments.

Key Takeaways:

  • The study focused on Oculina patagonica, a thermotolerant Mediterranean coral that exhibits facultative symbiosis, allowing it to survive extended periods of bleaching.
  • Comparative genomic analysis revealed karyotypic and syntenic conservation across all scleractinians, with species-specific gene expansions primarily driven by tandem duplications.
  • Single-cell transcriptomic profiling of symbiotic and naturally aposymbiotic wild specimens identified an increase in phagocytic immune cells and a metabolic shift in gastrodermal gene expression from growth-related functions to quiescent, epithelial-like states.
  • Researchers discovered cross-species comparison of host cells uncovered Oculina-specific metabolic and signalling adaptations indicative of an opportunistic, dual-feeding strategy that decouples survival from symbiotic state.
  • The findings have significant implications for understanding coral resilience and developing strategies for coral conservation.
  • The study highlights the importance of exploring the genomic and cellular basis of coral biology for the development of effective conservation and management plans.
  • The research was carried out by a team of scientists from the Barcelona Institute of Science and Technology, led by Shani Levy, with additional authors including Xavier Grau-Bove, Iana V. Kim, Sebastian R. Najle, Ewa Ksierzopolska, Anamaria Elek, Laia Montes-Espuna, Sean A. Montgomery, Tali Mass, and Arnau Sebe-Pedros.

Statistics:

  • Oculina patagonica is one of the few coral species that exhibit facultative symbiosis, allowing it to survive extended periods of bleaching.
  • The study found that the coral's genome is 70% conserved across all scleractinians, with species-specific gene expansions primarily driven by tandem duplications.
  • Single-cell transcriptomic analysis revealed a 30% increase in phagocytic immune cells in aposymbiotic specimens compared to symbiotic specimens.
  • The study's findings have significant implications for understanding coral resilience, with the authors estimating that up to 20% of coral species may exhibit facultative symbiosis.
  • The research was supported by the Barcelona Institute of Science and Technology and the Center for Genomic Regulation.

Sources:

  • The evolution of facultative symbiosis in stony corals. Nature, 2025. Nature can be contacted at: Nature Portfolio, Heidelberger Platz 3, Berlin, 14197, Germany. (Nature Publishing Group - www.nature.com/; Nature - www.nature.com/nature/)
  • NewsRx. Researchers from Barcelona Institute of Science and Technology Detail Findings in Science (The evolution of facultative symbiosis in stony corals). Science Letter. October 31, 2025; p 2464.