Dinoflagellate plankton glow so that their predators won’t eat them

Source: Science Daily

Some dinoflagellate plankton species are bioluminescent, with a remarkable ability to produce light to make themselves and the water they swim in glow. Now, researchers have found that for one dinoflagellate species (Lingulodinium polyedra), this bioluminescence is also a defense mechanism that helps them ward off the copepod grazers that would like to eat them.

https://www.sciencedaily.com/releases/2019/06/190617110538.htm