Deep Sea Hatchet Fish: Named for their shape, these little beauties range from 1-6 in. & are very thin. They have large upward facing eyes that are thought to be used to locate prey above them. They're vertical migrators, meaning that they swim from the depths to upper waters to hunt. Possibly on plankton and small fish. And what makes these guys so neat? They sport a very fashionable ventral (belly) bioluminescence. ….They glow!