The piranha is generally around 30cm long but some piranha individuals have been found measuring nearly 80cm. The piranha is said to be more feared by many humans than even a shark.
Piranhas are generally found in fast flowing rivers and streams where there is plenty of food for the piranha to eat. The piranhas lives together in large shoals and constantly compete for food. Feeding frenzies will be triggered when there is a shortage of food or blood in the water.
Piranhas tend to breed in pairs in slower water such as lagoons generally during the rainy season around April to May. The mating pair prepare a nest that the female piranha lays clusters of eggs in. The female piranha lays an average of 5,000 eggs and due to the fact that the male piranha and the female piranha defend their protected eggs so effectively, more than 90% often survive and hatch after just a few days.
In August 2009 a 35cm piranha was found in a river in Devon, thousands of miles from it's native home. The team that discovered the piranha were utterly bewildered as to what this tropical fish was going in a river in England but later deduced that this piranha must have been kept as a pet and then released due to the fact that it was eating sweetcorn.