Discovered in the deep: the fish with razor-sharp fangs too big for its mouth

The charismatic deepsea viperfish has teeth which interlock forming an inescapable, glassy cage to trap preyDeep-sea viperfish have razor-sharp fangs so big they don't fit inside their mouth, but they interlock in front of their jaws forming an inescapable, glassy cage. "When people think of deep sea fishes, the viperfish is one of the first things that comes into their mind," says Yi-Kai Tea, a fish expert from the Australian Museum in Sydney. "They're very charismatic, very iconic."Tea found a Sloane's viperfish (Chauliodus sloani) on a research expedition that recently returned from the remote waters of the Indian Ocean around the islands of Cocos (Keeling). This species is relatively common in open waters of the twilight zone, between about 500 and 1,000 metres down, so it was a surprise to find this one in the trawl net that Tea and his team were using to sample animal life closer to the seabed.The viperfish's splendid teeth not only form a trap for prey, but they're very difficult to see. "Having really transparent, big teeth, allows you to conceal something that is otherwise very obvious and very evident," says Tea.A few years ago, a study of a closely related species of deep-sea fish, the shiny loosejaw (Aristostomias scintillans), uncovered the secret of their see-through teeth. They're made of enamel and dentine, the same substances as human teeth. The intricate nanostructure of their teeth scatters very little light and instead lets it pass straight through. This means the fish's teeth don't twinkle in the bioluminescent lights made by so many animals in the deep sea. Continue reading...