Within OCEAN CITIZEN, research activities in the pilot site of Eilat focus on model coral species such as Stylophora pistillata, supporting studies on coral growth, reef restoration and carbon dynamics in the Red Sea.
Eilat is located at the northern tip of the Gulf of Aqaba, in the Red Sea, and is characterised by tropical coral reefs dominated by stony corals (order Scleractinia), which build calcium carbonate skeletons that form the structural foundation of the reef. Like most reef-building corals, they live in symbiosis with microscopic dinoflagellate algae known as zooxanthellae. The coral provides the algae with a protected environment, while the algae, through photosynthesis, supply oxygen and organic compounds, mainly sugars, that constitute the coral’s primary source of energy.
Among the 120–180 coral species found in Eilat, one of the most abundant and ecologically important is Stylophora pistillata, commonly known as the cauliflower coral. This branching species exhibits a relatively fast growth rate and thrives across a wide depth range, from shallow reef flats to mesophotic zones1. Its compact, bush-like canopy provides shelter and habitat for numerous reef organisms, including Trapezia crabs, anthias (Pseudanthias squamipinnis), Chromis damselfish, scorpionfish, brittle stars and more2.
While S. pistillata relies heavily on its symbiotic algae for nutrition, it can also feed heterotrophically by capturing plankton from the water column. Despite this adaptability, S. pistillata, like many tropical corals, remains vulnerable to the impacts of global and local stressors. Elevated sea temperatures can cause the loss of its symbiotic algae, resulting in coral bleaching, while human pressures such as pollution, sedimentation, and intensive diving activity further threaten its health.
In Eilat, it has a long reproductive season, in which it releases ready-to-settle planulae for 8-9 months a year, every day, independently of the lunar cycle3. Its extended reproductive season, fast growth, and structural complexity make it a keystone ecosystem engineer, vital for reef restoration. These characteristics have also made it one of the most studied coral species worldwide and a cornerstone model organism in coral biology, physiology, and restoration science. In the ornamental trade, it is known as the “Milka coral,” recognisable by its white branch tips, which indicate active growth.
Photo credits: Dor Shefy.
Both the Israel Oceanographic and Limnological Research institute (IOLR) and the company V-Corals in Eilat use S. pistillata as a model species in their research, spanning multiple ecological scales, from the physiology of individual colonies to large-scale reef restoration and ecological engineering1.
V-Corals, a private company based in Eilat, develops coral-growth technologies for both the ornamental trade and reef restoration. In its inland facility, V-Corals cultivates over 180 morphs from 60 coral species. Within the OCEAN CITIZEN consortium, S. pistillata serves as one of the key model organisms for assessing growth performance and optimising husbandry protocols under controlled conditions. The company tests how factors such as light intensity, water chemistry, substrate type and feeding regimes affect coral growth and health, with the aim of developing scalable solutions for restoration and sustainable aquaculture.
At IOLR, S. pistillata plays a central role in research aimed at quantifying carbon dynamics in floating reefs. Although corals are animals that produce calcium carbonate, a process that releases CO₂, they also act as complex carbon processors through their symbiotic relationship with photosynthetic algae. The photosynthesis performed by the zooxanthellae, coupled with the coral’s capacity to recycle organic carbon within its tissues and mucus, makes floating reefs potential contributors to carbon capture and storage in marine systems4.
S. pistillata in the floating reef in Eilat. Photo credits: Dor Shefy.
Beyond carbon studies, IOLR is advancing innovative restoration techniques using S. pistillata as a biological model. These include creating coral chimeras (fusion of genetically distinct individuals) to enhance genetic diversity and stress tolerance5, assembling “mega-colonies” to accelerate structural recovery, and studying population dynamics to inform the design of more resilient restoration frameworks6. Such research bridges ecological theory with applied conservation, helping to shape the next generation of reef restoration strategies in the Red Sea and beyond.
1. Shefy, D., and Rinkevich, B. (2021). Stylophora pistillata—A Model Colonial Species in Basic and Applied Studies. In Handbook of Marine Model Organisms in Experimental Biology (CRC Press), pp. 195–216. https://doi.org/10.1201/9781003217503-11.
2. Shmuel, Y., Ziv, Y., and Rinkevich, B. (2022). Strahler Ordering Analyses on Branching Coral Canopies: Stylophora pistillata as a Case Study. J Mar Sci Eng 10. https://doi.org/10.3390/jmse10010121.
3. Shefy, D., Shashar, N., and Rinkevich, B. (2018). The reproduction of the Red Sea coral stylophora pistillata from Eilat: 4-decade perspective. Mar Biol 165, 1–10. https://doi.org/10.1007/s00227-017-3280-0.
4. Rinkevich, B. (2024). A conceptual approach for an innovative marine animal forest apparatus that facilitates carbon sequestration and biodiversity enhancement. Science of the Total Environment 947. https://doi.org/10.1016/j.scitotenv.2024.174353.
5. Shefy, D., Shashar, N., and Rinkevich, B. (2020). Exploring traits of engineered coral entities to be employed in reef restoration. J Mar Sci Eng 8, 1–15. https://doi.org/10.3390/jmse8121038.
6. Rachmilovitz, E.N., Douek, J., and Rinkevich, B. (2024). Population Genetics Assessment of the Model Coral Species Stylophora pistillata from Eilat, the Red Sea. J Mar Sci Eng 12. https://doi.org/10.3390/jmse12020315.
