Coral cares for algae

This is a particularly weird and interesting story that I heard on NPR this morning in a segment called "Pulse of the Planet" presented by the National Science Foundation. You can go to the website and listen to the 2 minute piece, or read it below:

http://www.pulseplanet.com/dailyprogram/dailies.php?POP=4205

In a coral reef, the coral provides a kind of skeleton, a home for the algae that live in its tissues. And in return, the algae convert sunlight into food that the coral lives on. Well, now it turns out that coral may be helping the algae in other ways, giving coral reefs a mysterious glow..

Vincent Pieribone is an assistant professor at the Yale University School of Medicine.

"So, the coral need these algae in their tissue to produce food for them. But the algae need light of a certain wavelength, a sort of reddish to orangish light, in order to produce this food. However, as the coral moves into deeper depths of water, the water blocks out a lot of the oranges and the yellows and the red, and the only light that makes it down that depth are blues and greens as you get deeper. So one idea is that the coral produce the special proteins that they put around the little crypts that contain these algae, so that when this blue light that does make it down to depth, this protein absorbs the blue light and converts it through an amazing process into an orange or yellow or red light that is then reemitted and the algae absorb that light and so that they can survive, they can produce food for the coral." Thanks to the special properties of the coral's proteins, they'll glow in shades of orange, yellow or red, even in the depths of the ocean.

"The interesting thing about these proteins is that they don't actually produce light, they take the sunlight that comes down and they convert that into a color of light that can be used by the algae. There's other reasons people believe these proteins might be there, for example, for the tissues of the coral to protect them against the cancerous effects of sunlight. That's part of what we're planning to do is to try to understand what these different functions of these proteins are."

I'm Jim Metzner, and this is the Pulse of the Planet.