Piranhas

Research on the species Serrasalmus aff. brandtii and Pygocentrus nattereri in Viana Lake, which is formed during the wet season when the Rio Pindare (a tributary of the Rio Mearim) floods, has shown that these species eat vegetable matter at some stages in their life; they are not strictly carnivorous fish.
Relationship with humans
Piranha teeth are often used to make tools and weapons by the indigenous population. Piranhas are also popular as food, although if an individual piranha is caught on a hook or line, it may be attacked by other (free) piranhas.