Scientists are studying the biology behind this mesmerizing mating ritual, first spotted by Christopher Columbus.
Bermuda fireworms are tiny sea dwellers that ordinarily wouldn’t attract much attention: they’re less than one inch long, and live concealed among corals and algae on the seabed. But during mating season, they turn into something spectacular, lighting up the water with bioluminescence. The night before Christopher Columbus landed in the New World, he may have been a lucky witness to the ritual, seeing the flickering glow in the ocean “like the light of a wax candle.”
The ritual is a precisely timed, glamorous affair. It happens on the third night after the full moon both summer and fall, 55 minutes after sunset. Spawning females start to secrete their bright blue-green luminescence to attract males. They swim in tight circles as they glow, creating “a field of little cerulean stars across the surface of jet black water,” describes Mark Siddall, a curator in the Museum’sand author of a new study that examines the fireworms’ mating behavior. “Then the males, homing in on the light of the females, come streaking up from the bottom like comets—they luminesce, too. There’s a little explosion of light as both dump their gametes in the water.” Siddall calls it “the most beautiful biological display I have ever witnessed.”
Researchers studied the mesmerizing ritual, and discovered that the Bermuda fireworm’s glow came from an enzyme called luciferase (fireflies also have a form of luciferase). The type of luciferase enzyme found in the fireworm were brand new: they have never been detected in any other species. “It’s particularly exciting to find a new luciferase because if you can get things to light up under particular circumstances, that can be really useful for tagging molecules for biomedical research,” said co-author Michael Tessler, a postdoctoral fellow in the Museum’s Sackler Institute for Comparative Genomics.