Pronounced Polyps
This flowery tower is an underwater image of a community of coral polyps under blue light. The blue light makes naturally fluorescent compounds in the polyps shine pink and orange.
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DownloadPronounced Polyps
This flowery tower is an underwater image of a community of coral polyps under blue light. The blue light makes naturally fluorescent compounds in the polyps shine pink and orange.
What am I looking at?
This is a darkfield, focal stacked image of a group of individual granulosa coral polyps (1) in the genus Acropora; it was taken under a blue light source, which shows off the polyps’ natural pink and orange fluorescence.
Biology in the background
Coral reefs are made of communities of living coral animals that populate the rocky skeletons of their ancestors. An individual coral animal is called a polyp. These polyps live in large groups that form the structures that most people think of when they hear the word “coral.” When these polyps die, they leave behind calcified skeletons that form an interconnected network of rock on which live coral polyps settle and grow.
Coral polyps are filter feeders – extending retractable protrusions (the flower-shaped extensions in this image) into the surrounding water to pull small plants and animals into their stomachs. They are very sensitive to water temperature, so as ocean temperatures rise due to global warming, many coral species are dying off in their natural habitats – a process called “coral bleaching.”
The polyps in this image are about 1 millimeter wide, or roughly 13 times larger than a human hair.
Technique
This image was created using darkfield microscopy, focal stacking, and blue light illumination.
Pichaya Lertvilai, University of California, San Diego Scripps Institution of Oceanography