Here's a question - if piranhas are so ferocious and will attack anything, why aren't they the only fish in the Amazon? Well, in some cases, it's because other fish possess bite-proof armor. The 300-pound (136-kg) Arapaima is just such a fish. In the dry season, when water levels get low, Arapaima are forced to share relatively small bodies of water with piranhas. Their tough-but-flexible scales, however, allow them to remain unharmed. A scientist from the University of California, San Diego is now taking a closer look at those scales, with an eye towards applying their secrets to human technology such as body armor.
LINK (Via: Gizmag)