A photophore is a glandular organ that appears as luminous spots on various marine animals, including fish and cephalopods. The organ can be simple, or as complex as the human eye; equipped with lenses, shutters, color filters and reflectors, however unlike an eye it is optimized to produce light, not absorb it. The bioluminescence can variously be produced from compounds during the digestion of prey, from specialized mitochondrial cells in the organism called photocytes ("light producing" cells), or, similarly, associated with symbiotic bacteria in the organism that are cultured.
Photophores are found on some cephalopods, including firefly squid, the sparkling enope or firefly squid, which can create impressive light displays, as well as numerous other deep sea organisms such as the pocket shark Mollisquama mississippiensis and the strawberry squid.
Arrangement of various photophores on the squid Lycoteuthis lorigera
Photophores on a lanternfish, the most common deep sea fish worldwide
- "Cephalopod Photophore Terminology". Tolweb.org. Retrieved 2012-08-30.
- Scribner, Herb (2019-07-23). "This glow-in-the-dark shark was recently discovered. Here's what we know". Deseret News. Retrieved 2020-08-06.