Deep-SeaSharksUseBiofluorescenceforSecretCommunicationinDarkWaters

A collaborative team from the American Museum of Natural History and the City University of New York (CUNY) discovered that several deep-sea shark species, including the chain catshark and the swellshark, possess biofluorescence, absorbing blue light and re-emitting it as green light. This unique ability was observed during expeditions to the Eastern Pacific, where researchers used specialized lighting to photograph the glowing sharks in their natural deep-water habitats. The study revealed specific biofluorescent patterns on their skin, appearing as distinct light and dark markings, which are invisible under normal deep-sea conditions. The surprising implication is that these sharks utilize a 'secret' communication channel, visible only to other biofluorescent marine life, allowing for discreet interactions in the perpetual twilight zone. This groundbreaking research was published in *PLOS ONE* in 2014.