The piranha is one of the most aggressive fish that exists. Its tall and laterally compressed body, its prominent head and the position of the mouth give it a very striking appearance when seen from the front. Its teeth are numerous, small and sharp. The reddish and intense coloration is very characteristic of this piranha, located mainly in the anterior region of the chest and pectoral fins.

This species gathers in large groups of hundreds and even thousands of individuals, poorly organized, but acting in unison when large prey is within reach. If an injured mammal falls into the water, they are able to smell it from a great distance. They will follow the trail and begin to bite very aggressively and quickly at the animal's body, which in a few minutes is reduced to a set of bones.