Bioluminescent dinoflagellates set the waves aglow off San Diego.JOHN H. MOORE
Lingulodinium polyedrum, a species of marine dinoflagellate (from the Latin for “whirling tail”), proliferates in the warm waters off the coast of San Diego every year. It produces a bioluminescent glow when disturbed—whether by predators or breaking waves—and when the organisms gather in large numbers, the effect can be beautiful. John H. Moore took this photo in Torrey Pines State Natural Reserve, San Diego, California.