Glowing Sharks - David Gruber

Deep beneath the sea, where the sun's rays are unable to penetrate, sharks, fish and other animals too strange to be fictional lurk. And they glow in the dark. National Geographic Emerging Explorer David Gruber explains how and why these creatures glow, although the answer usually seems to involve mating or eating. He also tells the story of how the angler fish is able to harvest a very specific type of bacteria that, when gathered in enough concentration, allows them to shed an eerie glow that allows them to lure their prey. Gruber also explains how science is learning to put nature's natural glows to work in hospitals.