Bioluminescence is the ability of an organism to create light through chemical reactions. Creatures use bioluminescence in many ways: to light their way, attract prey, or seduce a mate. Many underwater animals are bioluminescent—from the viper fish to the various species of flashlight fish, named for their light.[3] Some creatures, such as the angler fish, have a concentration of photophores in a small limb that protrudes from their bodies, which they use as a lure to catch curious fish.