The Amazon River is filled with mysterious creatures, and one of those is the piranha. Almost everybody knows what a piranha can do and yes, they're real. They're carnivorous fishes and they can strip a carcass in a matter of minutes.

But what about those who share the River with these animals? A new study has led researchers to discover that a certain specie of fish has developed a “bullet-proof vest” to protect itself from the knife-like teeth of a piranha.

According to Fox News, Arapaima gigas has come up with a medieval-like way to shield itself from a piranha attack. The fish's scales have a tough yet flexible inner layer held together by collagen to mineralize the scale's outer layer. Think of the gigas, or more commonly known as pirarucu, as a living, swimming suit of armor.

The study was conducted by researchers from the University of California, San Diego and University of California, Berkeley. Their study, according to Reuters, came with a promise that the pirarucu can be a blueprint for the creation of better body armor to protect people from danger, as well as “applications in aerospace design.”

Eurekalert, who also reported on the new discovery, said that the layers on the pirarucu's scales are like real bullet-proof vests: they are made up of several layers “sandwiched between layers of hard plastic.”

It added that while other fish use collagen, those found in the pirarucu proved to be thicker. In fact, its scales are as thick as a grain of rice and it's enough to stop a piranha from penetrating its innards.

UCSD materials scientist and lead researcher Wen Yang pointed that the fish's “natural armor” may be similar to the armor humans use “because of the similar scale overlapping system,” the natural armor proved to be tougher and lighter and it does not prevent its user from any movement.

“ Remeber that the fish scales were developed through hundreds of millions of years. They are very advanced,” said Yang.

Aside from being as tough as nails, the pirarucu's scale system can only be deformed; a piranha's bite – no matter how strong it may be – will not tear, break or pierce the fish's scales.

Piranhas
While it is rare for flesh-eating piranhas to attack humans, 15 swimmers were bitten over the weekend at the Daveron beach on the Paraguay River in Brazil. REUTERS

Evolution has made it possible for animals to defend themselves from their predators. From the quills of the hedgehog to the super strong scales of the armadillo, these animals are making a stand and letting those on top of the food chain know that they're not going down without a fight.

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