Courtesy: Jacobs School of Engineering

Piranhas are not known to peacefully co-exist with other creatures, but one Amazonian fish has been doing just that, leading scientists to believe its scales could hold the key to creating better military body armor.

The arapaima fish, which weigh in at an average of  300-pounds, have intricately designed scales that act like flexible body armor for the ancient fish.

"Piranhas will attack anything for food. If you fall in the lake in October, there is not much hope for a person," said Marc Meyers, professor at the Jacobs School of Engineering at University of California San Diego.

Meyers said he was fascinated how the arapaima could survive in a piranha-filled lake when no other species could and decided to set up a laboratory experiment using a piranha tooth and arapaima scales.

Meyers found that the teeth could partially penetrate the scale, but cracked before they punctured the muscle.

"The scale of the fish is hard and at the same time it is flexible," he said.

Meyers, who has been going to the Amazon for decades, saw an opportunity. He previously worked on military projects before he got into biological research.

"This could be used to create flexible ceramics," he said, pointing to military body armor as one potential use.

But he believes there could be many uses for his unique finding.

"You match a discovery with a need," he said.