Clockwork Sex of Coral Reef Algae
Mlot, Christine, Science News
Birds and bees do it-and we know in fairly intimate detail how they do it-but sexual reproduction among algae is often a secretive, little-studied affair. Cryptogams, they have been called, because of their hidden sex lives. Now, a chance observation by a fish ecologist sheds new light on how algae in a group important to coral reefs get their gametes together.
The insight had a lot to do with being in the right place at the right time: the coral reefs off Panama at 5 a.m. Kenneth E. Clifton and his coworkers at the Smithsonian Tropical Research Institute went snorkeling each morning to monitor fish reproduction on the reef. On one of the dives, Clifton says he "saw these algae smoking," puffing out plumes of milky green cells.
After more than a year of studying the algae and timing their eruptions, Clifton pieced together the first detailed picture, reported in the Feb. 21 Science, of how the algal community organizes sexual reproduction. "Most of these kinds of events, if they are studied at all, are only studied in the lab," says Mark Hay, a marine algae specialist at the University of North Carolina at Chapel Hill. "This is a huge step forward."
Commonly called seaweed, the algae sprawl and drape on and around coral reefs worldwide. They often show up on satellite images. As photosynthesizers, they are food for the reef organisms. Some species cut down on this predation with an internal, shell-like structure of calcium carbonate that may interfere with digestion in fish, says Clifton, now at the University of California, Santa Cruz. …