Bioluminescent organisms create their light from within, using chemical reactions that emit photons. There are seven known types of protein structures involved in producing bioluminescence, including luciferin and luciferase. The glow from these animals can be used for a range of purposes, such as attracting a mate, scanning for prey, or scaring off a predator. There are a wide range of bioluminescent species, only a small selection of which are shown here. Assisted bioluminescence occurs in organisms that symbiotically house and protect another organism that produces light, but don’t directly produce light themselves.