Below 200 meters, where sunlight is only a glimmer, light—in the form of bioluminescence—is still an important way to communicate, find mates, and avoid predation. And in this barely visible light from above and within the twilight zone, new research shows that some deep-sea fish are able to avoid detection by absorbing nearly every photon that lands on them.
A team of scientists from Duke University, Natural History Museum in London, Smithsonian National Museum of Natural History, and Monterey Bay Aquarium Research Institute found that black-skinned fish, like dragonfish and fangtooth, are capable of absorbing more than 99.5% of light. As a result, even in the presence of bioluminescence, these fish, some of which produce the blackest organic material known, can avoid detection as they navigate the vast volume of the ocean’s depths. “If you want to blend in with the infinite blackness of your surroundings, sucking up every photon that hits you is a great way to go,” said Karen Osborn, a co-author of the study and a research zoologist at the Smithsonian National Museum of Natural History.
Davis AL, et al., 2020 “Ultra-black Camouflage in Deep-Sea Fishes,” Current Biology 30, 1-7.