Vicente Fernandez
Orr Shapiro
Melissa Garren
Theresa Santiano-McHatton
Roman Stocker
Department of Civil and Environmental Engineering
Massachusetts Institute of Technology (MIT)

Orr Shapiro
Assaf Vardi
Department of Plant Sciences
Weizmann Institute of Science
Rehovot, Israel

Image Credit: Stocker Group, Civil and Environmental Engineering, MITTracks of fluorescent beads reveal the complex cilia-driven flow between Pocillopora damicornis coral polyps. Each polyp is approximately 1 millimeter in diameter.

Hair-like cilia are known to cover the entire surface of reef-building corals, but their influence on the boundary layer and local environment of the animal has been overlooked. In this image, the complex cilia-driven flow between Pocillopora damicornis coral polyps is captured by tracks of fluorescent beads. The bundles of arced tracks over the coral surface capture the mixing that is occurring perpendicular to the surface. This ciliary mixing is enhancing mass transport near the coral surface, potentially increasing rates of photosynthesis and carbon fixation by the coral-algal symbiotic system and also affecting invasion of the coral surface by microbial pathogens.

The composite image is generated from 120 video frames taken at 10 frames per second by use of video microscopy. The tracks of the 2-micrometer fluorescent particles are shown superimposed on a single frame to illustrate the relationship between flow and polyp locations. Each polyp is approximately 1 millimeter in diameter, about a thousand times larger than the fluorescent beads. Naturally occurring green fluorescent protein (GFP) gives the coral its green appearance.

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This image can be freely reproduced with the accompanying credit: "Stocker Group, Civil and Environmental Engineering, MIT."

Contact Information

 Vicente Fernandez
Department  of Civil and Environmental Engineering
MIT 48-211
77 Massachusetts Ave.
Cambridge, MA 02139
Tel. : 857 998 1954
vicentef@mit.edu