KINGDOM: Animalia (Animals)
PHYLUM: Chordata (Possessing a notochord)
CLASS: Actinopterygii (Ray-finned fishes)
ORDER: Characiformes (Characins and their allies)
FAMILY: Characidae (Characins)
SUB-FAMILY: Serrasalminae (Serrated bellied fish)
GENUS: Pygocentrus (Piranhas)
SPECIES: Pygocentrus nattereri (Natterer’s Piranha)
Natterer’s piranhas are widely distributed throughout the South American continent. They can be found in tropical freshwater rivers in Argentina, Bolivia, Brazil, Colombia, Ecuador, Guyana, Paraguay, Peru, Uruguay and Venezuela.
The Natterer’s piranha is a ray-finned fish with a red belly, a grey body and silver flecked scales on the sides. They have a dark grey head that is orange-red below, and silvery, red-flecked eyes.
Natterer’s piranhas prefer tropical white water rivers. The also occur in some streams, lakes and flooded forests.
Piranhas are omnivores (eating almost anything nutricious). Despite their infamous reputation as being dangerous and unpredictable monsters they are mostly scavengers. They also do not exhibit group hunting behaviour. They mainly eat fish, insects and aquatic invertebrates, such as molluscs and crustaceans but will also eat small mammals, fruits, seed, algae and aquatic plants. Occasionally Natterer’s piranhas may enter into a ‘feeding frenzy’, where schools of piranha converge on a large item of prey and strip it clean within minutes, but frenzies are not usually random attacks, and are more often the result of provocation or starvation.
Natterer’s piranhas live in groups (called schools) of 20 or more individuals. It is thought that this is for the purpose of protecting themselves against predators. Piranhas are very territorial, especially at spawning time.
Natterer’s piranhas are serially monogamous (having one partner at a time for a period, before moving on to the next partner). They seem to have a type of courtship display that involves swimming in circles. The male will build a bowl-shaped nest in the sediment, wherein the female will lay several thousand eggs to be fertilised by the male.
Eggs are laid in clusters and are attached to submerged aquatic vegetation. The male guards and tends the eggs and is very territorial during this time. The eggs will hatch after two or three days and the baby piranhas are independent from birth. After hatching, the young piranhas stay hidden amongst plants. Once they are large enough to defend themselves they will leave their hiding place. Sexual maturity is reached at about 18 months of age. They can live for more than 10 years.
Piranhas are preyed upon by large, predatory Amazon fish, the pink dolphin, as well as fish-eating birds such as egrets and storks.
Though the species is not considered threatened, the collection and trade of the species to aquariums may be causing a low risk to the Natterer’s piranha.
Did you know?
- A piranha’s formidable teeth are not usually visible, being covered by thick, fleshy lips
- They have an advanced sense of smell, which helps them locate prey
- Piranhas act as their environment’s natural cleaners, consuming any decaying matter and injured animals
- When taken out of the water, Natterer’s piranhas emit a low-frequency harmonic sound