December 10, 2009
‘Like swimming in a snow globe’
I’ve been bringing you updates from our folks in Copenhagen this week. Today I’ve got a brief, but related, break in the action for you. And it’s about coral sex.
In this month’s issue of Smithsonian Magazine, Megan Gambino follows renowned coral reef biologist Nancy Knowlton to Panama on her annual pilgrimage to watch tropical corals spawn.
Most corals are hermaphroditic “broadcast spawners,” which means they release sacs containing both eggs and sperm, synchronizing their spawning with neighboring coral colonies. How do they know it’s time to get busy? Scientists think the corals use three cues: the full moon, sunset, which they sense through photoreceptors, and a chemical that allows them to “smell” each other spawning. Pretty phenomenal, huh?