Combined responses of primary coral polyps and their algal endosymbionts to decreasing seawater pH

• Published in: Proceedings of the Royal Society B: Biological Sciences
• Main Authors: Scucchia, Federica, Malik, Assaf, Zaslansky, Paul, Putnam, Hollie M., Mass, Tali
• Other Authors: Israel Science Foundation, Binational Science Foundation, H2020 European Research Council
• Format: Article in Journal/Newspaper
• Language: English
• Published: The Royal Society 2021
• Subjects: Ocean acidification
• Online Access: http://dx.doi.org/10.1098/rspb.2021.0328; https://royalsocietypublishing.org/doi/pdf/10.1098/rspb.2021.0328; https://royalsocietypublishing.org/doi/full-xml/10.1098/rspb.2021.0328

With coral reefs declining globally, resilience of these ecosystems hinges on successful coral recruitment. However, knowledge of the acclimatory and/or adaptive potential in response to environmental challenges such as ocean acidification (OA) in earliest life stages is limited. Our combination of physiological measurements, microscopy, computed tomography techniques and gene expression analysis allowed us to thoroughly elucidate the mechanisms underlying the response of early-life stages of corals, together with their algal partners, to the projected decline in oceanic pH. We observed extensive physiological, morphological and transcriptional changes in surviving recruits, and the transition to a less-skeleton/more-tissue phenotype. We found that decreased pH conditions stimulate photosynthesis and endosymbiont growth, and gene expression potentially linked to photosynthates translocation. Our unique holistic study discloses the previously unseen intricate net of interacting mechanisms that regulate the performance of these organisms in response to OA.