Bioluminescence (light produced by a chemical reaction that originates from the organism) is common in deep sea creatures such as squids and cuttlefish, but it is very rare among octopods. Light organs have only been seen in breeding octopod females of two genera. The exciting discovery of bioluminescence in a deep-sea finned octopod, Stauroteuthis syrtensis, is the focus of this week's In the News. The blue-green light is emitted from the octopods' suckers, which have characteristics of both photophores and suckers. Lack of fossil records of bioluminescence has made it difficult to study the evolutionary history of light production. However, since these modified suckers have retained structural characteristics of their previous function (adhesive suckers), this offers a rare opportunity to view the evolutionary history of light production. Senior Scientist, Edith Widder, at the Harbor Branch Oceanographic Institution (HBOI) explains it as an example of an evolutionary transition, in the March 11th issue of Nature (1999, 398:113-114). Widder believes that the "change from sucker to light organ may have occurred during colonization of the deep open-ocean by a creature that was originally a shallow-water bottom-dweller." Furthermore, it is hypothesized that these modified suckers may now function to attract prey and to visually communicate. The six sites listed provide information about this discovery along with background information on bioluminescense and octopods.