Why do some animals have bioluminescent features?

Some animals have bioluminescent features to attract prey, communicate, or deter predators. In deep-sea environments, where sunlight does not reach, species like anglerfish use bioluminescence to lure prey. Others, such as jellyfish, emit flashes of light to startle predators. Bioluminescence also aids in mating displays, as seen in fireflies, and serves as camouflage for some species by breaking up their silhouette.