Dinoflagellates are the most common sources of bioluminescence at the surface of the ocean.
The flashlight fish has light organs under each eye. These organs contain about a billion bioluminescent bacteria. The flashlight fish uses these glowing bacteria-filled organs to locate or lure prey. The bacteria do not harm the flashlight fish.
Fireflies, from the family Lampyridae, are beetles, not flies. During the mating season, fireflies use specific flash pattern codes to locate members of their own species.
While there are no bioluminescent multicellular plants, over forty glowing fungi (mushrooms) have been identified.
The bright red decapod shrimp (Acanthephyra purpurea) will actually "vomit" bioluminescent chemicals into the face of a predator as it flips backwards to escape in the dark ocean. This activity is similar to the way a squid will squirt black ink to distract a predator while it gets away.
The belly of the cookie-cutter shark is covered with thousands of tiny blue photophores, or belly lights. They may use this light to attract prey.
New Zealand Glowworms are not worms, but fly (not firefly) larvae. They live on the ceilings of caves where they spin shining sticky threads like shimmering fishing lines. Flying insects attracted to the light are caught on these lines. The glowworms then haul up their lines, eat the captured prey, and throw the line back for another catch.