A gland or organ that is specialized for the production of light (see bioluminescence). Photophores are a common feature of invertebrates and fish living in the deep sea, often being arranged in lines or other patterns over the body surface to produce a characteristic display of light. They contain the light-producing chemicals or symbiotic bacteria responsible for the bioluminescence. The cells of many different tissues can be modified to form a photophore, including mucous glands in various fish and even the suckers of some deep-sea octopuses.
Subjects: Biological Sciences.