Bioluminescent bacteria glow in the ocean for the same reason roadside eateries display neon signs: They want to attract hungry diners.
New laboratory experiments bolster the longstanding theory that marine bacteria light up to get themselves a free ride to other parts of the ocean in the digestive tracts of larger beasts, scientists from Israel and Germany report online December 27 in the Proceedings of the National Academy of Sciences.
“It’s terrific to see this experiment,” says J. Woodland Hastings, a bioluminescence expert at Harvard University who was not involved in the research. “It’s nice to see these ideas confirmed.”
Many deep-sea creatures, from bacteria to fish to squid, are bioluminescent — meaning they generate light inside their bodies through chemical reactions. Different organisms glow for different reasons; the anglerfish, for instance, can light up a lure to attract prey, while some plankton glow when disturbed to attract predators of whatever is stirring them up.