While deep areas of the ocean are almost completely dark, light still plays an important role in these environments. The ability of an organism to create its own light could put it at a competitive advantage in situations such as during the hunt for food, evading predators, or finding mates. Marine animals produce their own light primarily by three different processes: bioluminescence, fluorescence, and phosphorescence. This image shows a crab with fluorescent bristles on mouthparts.