Euphyllia paradivisa is a strictly mesophotic coral in the reefs of Eilat that displays a striking color polymorphism, attributed to fluorescent proteins (FPs). FPs, which are used as visual markers in biomedical research, have been suggested to serve as photoprotectors or as facilitators of photosynthesis in corals due to their ability to transform light. Solar radiation that penetrates the sea includes, among others, both vital photosynthetic active radiation (PAR) and ultra-violet radiation (UVR). Both types, at high intensities, are known to have negative effects on corals, ranging from cellular damage to changes in community structure. In the present study, fluorescence morphs of E. paradivisa were used to investigate UVR response in a mesophotic organism and to examine the phenomenon of fluorescence polymorphism. E. paradivisa, although able to survive in high-light environments, displayed several physiological and behavioral responses that indicated severe light and UVR stress. We suggest that high PAR and UVR are potential drivers behind the absence of this coral from shallow reefs. Moreover, we found no significant differences between the different fluorescence morphs’ responses and no evidence of either photoprotection or photosynthesis enhancement. We therefore suggest that FPs in mesophotic corals might have a different biological role than that previously hypothesized for shallow corals.
|State||Published - 1 Dec 2019|
Bibliographical noteFunding Information:
We would like to thank the Interuniversity Institute for Marine Sciences for making their facilities available to us. We thank N. Paz for proofreading, R. Tamir for diving assistance, and all of YL’s lab members for their support. We thank Dr. M. Kiflawi, T. Shlesinger, and R. Pickholtz for their statistical advise. We also wish to thank the editors and anonymous referees for their helpful comments. This research was funded by the Israel Science Foundation (ISF) grant agreement No. 1191/16 to YL, by the Ministry of Science, Technology & Space doctoral fellowship grant agreement No. 3–18487 to OBZ, and by the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie post-doctoral grant agreement No. 796025 to GE.
© 2019, The Author(s).