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The out-of-phase motion of coral tentacles and its impact on mass transfer

Wednesday, September 16, 2020

2:30pm – 3:45pm

Virtual via zoom (register by clicking here), Virginia Tech Campus

Uri Shavit

Department of Environmental and Civil Engineering

Technion, IIT


Corals rely almost exclusively on the ambient flow of water to support their respiration, photosynthesis, prey capture, heat exchange, and reproduction. We therefore study the flow around corals and investigate its impact on transport processes. During one of these studies, we analyzed the velocity field above a stony coral (Dipsastraea favus) when its tentacles were extended. As expected, the tentacles moved at the frequency of the surface waves but changed their direction before the water velocity changed its direction. We quantified this phase difference and found that it was about one quarter of the oscillation period. In this talk I will discuss the characteristics of the tentacle motion and analyze the coral benefits out of this phase difference (Ref.: Malul D., Holzman R., Shavit U., 2020, Coral tentacle elasticity promotes an out-of-phase motion that improves mass transfer, Proc. R. Soc. B, 287 (1929): 20200180).


Uri Shavit is a professor in the Department of Environment and Civil Engineering at the Technion in Israel. His BS and MS degrees are from the Technion and his PhD is from Carnegie Mellon University. His research group investigates flow and transport phenomena in complex environments such as stream vegetation, coral reefs, and small-scale marine environments. The research combines theory, numerical investigations, and experimental work at the Technion and at the Inter-University Institute (IUI) for Marine Sciences in Eilat, Israel. In 2019-2020, he spent a sabbatical leave at the Technical University of Denmark (DTU-Aqua).