Piranhas are usually 14 to 26cm long. Although some specimens have been reported to be up to 17.0  inches  (43cm) in length.

Newborn piranhas feed on zooplankton and eventually move on to small fish when older.

As United States President Theodore Roosevelt described piranhas in his book, Through the Brazilian Wilderness:

“They are the most ferocious fish in the world. Even the most formidable fish,the sharks or the barracudas,normally attack things smaller than themselves. But the piranhas habitually attack things bigger.”

Piranhas eat fish, crustaceans, aquatic plants, fruits, seeds, lizards, insects, carrion that reaches the water, birds, young caimans, baby anacondas, other piranhas and also capybaras.

This is a video about Piranhas: