They can grow to be a little over a foot long (30.5 centimeters) and weigh up to 4 pounds (1.81 kilograms).
Piranha are known for their razor-sharp teeth and relentless bite. In fact, the word piranha translates to “tooth fish” in the Brazilian language Tupí. With its sharp teeth and pack-hunting behavior, the piranha is imagined by many to be a ferocious predator, especially in Hollywood movies. But attacks on humans are extremely rare and there are no documented reports of someone being killed in a piranha attack.
Piranha feed on insects, fish, crustaceans, worms, dead animals, seeds and other plant material. A red-bellied piranha eats about one-eighth of its average body mass per day. It is primarily a scavenger, keeping the river clean by eating injured or dead animals. As their name suggests, red-bellied piranha have a reddish tinge to the belly when fully grown, although juveniles are silver with darker spots. Although piranha are fairly common, their numbers could be affected by the health of the Amazon River and surrounding land. They are illegal to own as pets in over 20 states in the U.S.