Fluorescence confocal microscope image of a live Polykrikos kofoidii cell, revealing how its light-producing molecule, luciferin, is distributed throughout the cell. In all other studied bioluminescent dinoflagellates, the fluorescence is visible only in certain vesicles. Credit: Brittany Sprecher and Michael Latz Scientists at UC San Diego's Scripps Institution of Oceanography have uncovered new insights into the bioluminescence of a unique species of marine plankton that feeds on other plankton, including the harmful algae responsible for red tides and algal blooms. Red tides occur when certain types of microscopic plankton, called dinoflagellates, rapidly multiply in the ocean, forming dense "blooms" that can discolor the water. The species most frequently behind these bloom events in Southern California is Lingulaulax polyedra (previously named Lingulodinium polyedra), which can produce spectacular bioluminescent displays at night during large bloom events.…