Deep sea animals have to live in a very cold, dark, and high-pressure environment where they can't see a thing! To survive there, they've evolved some very strange adapations. Some make their own light, an ability called bioluminescence, while others are totally blind. Some are terrifying looking, like anglerfish, while others are quite beautiful—even if there is no one to appreciate it except us people looking at photos. See some of the remarkable adaptations that deep-sea animals have evolved in this slideshow. Learn more about the deep sea and deep-sea corals at their overview pages, and see photos of other bioluminescent animals.