Scientific Name:
Pyocentrus nattereri (Kner 1860)

Common Names:
Red Bellied Piranha, Redbelly, Red Breasted Piranha, Red Piranha, Red, Piranha, Common Piranha, Gold Dust Piranha, Yellow King Emperor Piranha, 'Ternetzi' Piranha. The indigenous population call this species (Redbelly variation) Piranha Vermilla in Brazil, and Piranha Roja in Peru: both names mean Red Piranha.


Maximum Size:
40cm. (16") TL; specimen over 12" in the home aquarium are exceptionally rare.

Body Characteristics:
The Red Bellied Piranha is found in a variety of belly colors ranging from yellow and orange to red. Body colors are also as variable being; silver, gold, black. Some are so intensely gold-speckled that they are also commonly called "Gold Dust piranha" (the 'Ternetzi' variant found in the South of Brazil, Paraguay and Northern Argentina). The entire upper body is covered with beautiful shiny silvery spots. The tail, blueish with a vertical white band in the middle, is large and powerful, enabling them to swim very fast for short distances.
The head shape of these piranhas, like all other pygocentrus-species, is convex (ie. blunt and steep), but appears to be variable, some being very blunt-headed and having little to no concavity above the profile of the eyes. The nostrils are clearly visible, and divide the nasal opening in two sections. Their lower jaw is very muscular and powerful, although not as much as the other Pygocentrus-species. The eyes are large, placed in front of the head, have a diagonal dark line (for camouflaging the eyes) and become red when they reach about 3-4" in length.
Juvenile Redbellies have a more concave headshape, but that starts to change when they reach about 3-4" in length. Their body color is bright silver, with numberous dark spots. When they reach a length of about 2", their bellies and lower fins gradually become more yellow to red, and when they are about 3-4" in length, their body starts to turn darker, until it gets the adult steel blue/grey coloration. Like other Pygocentrus-species, the Redbellied Piranha tends to loose it's bright coloration when it gets ages. Very old specimen can be completely black or completely faded to a greyish coloration.
Locality map

Distinctive/unique features:
• No, or faint humeral spot.
• Red eyes.

Juvenile specimen can temporarily be housed in smaller tanks, preferably at least 32" (80cm.) in length. A smaller tank my work, but due to the very cannibalistic nature of juveniles this is not recommended (the casualty rate may be very high). Due to their territorial and hierarchical nature, mature specimen of this species need a large tank: a commonly used guideline is at least 20 gallons (80 liters) per fish, but this idea is somewhat flawed: gallonage says little about the shape and the footprint of the tank, which are the key factors in determining the desired tank size. As piranha species that live in groups require length and depth rather than height, the dimensions of the tank, the footprint to be more precise, determines how many fish a certain tank can house. The minimum recommended aquarium size for a group of for 3 fish is 48x20" (120x50cm.), 60x24" (150x60cm.) for a group of 4-5 fish, bigger still for a larger group.
Dure to the vast amount of waste this fish produces, as well as the poor table manners, a powerful and efficient filtration system is required. Ideal is a filter that is rated for at least 1,5-2 times the tank's size. A powerhead may be placed to provide additional currents, but keep in mind that these fish do not live in fast-flowing bodies of water in the wild.
Because of its shy and skittish nature, enough hiding places are required to give this fish a feeling of security. So a densely planted tank with lots of wood and/or rocks is ideal.

15°C 22-30°C 35°C

5.0 5.5-8.0 9.0
 Ideal conditions
 Suitable conditions
 Unsuitable conditions

Compatible Species:
Pygocentrus cariba, Pygocentrus piraya.

Captive Redbellies can be taught to eat almost everything meaty, ranging from live feeders (goldfish, rosy reds, minnows, tetras, basically anything small enough *), frozen fish (smelt, cod, catfish, salmon, tuna fish etc.), shrimp, krill, mussels, squid, insects and even small mammals (pinkies, mice....), reptiles and amphibians. Some owners have 'learned' their piranha's to eat food items such as fish flakes and pellets, and even seeds vegetables (such as cucumber), and fruit. Other make their own food cubes by blending different ingredients, ranging from pellets and food supplements designed for aquarium fish, to vegetables and meat, mix it with gelatine, and freeze it.
Mamalian meat/organs, small live mamals, reptiles, ampibians, poultry meat, dog- and catfood and even cheese are also often accepted, but should be fed very sporadically, if at all. Reason for this is that these food items are very rich in fat and protein, which makes it rather unhealthy sources of food. These food items at best only make up a tiny portion of this species' diet in the wild. This means that its digestive system is not designed to process these food items, and feeding these kinds of foods may also lead to digestive problems, obesity, decreased resistance against diseases and parasites, and possibly even fatal conditions.


Redbellies, like other Pygocentrus-species, catch living prey by active chase. They will charge a group of fish, snapping at anything they can get a hold of and will chase individual prey until caught. This may take some time, because although they are fast swimmers, they can only sustain high speeds for short bursts.
They also sometimes practice the ambush method, but often only get a fin or mouth full of scales rather than the whole fish.

The redbellied Piranha is one of the most wide spread species of Piranha in nature and the most common species in pet stores. Legendary in name and fame, this is the species most commonly associated with the word "Piranha", and the name alone is enough to bring up images of razorsharp teeth and gruesome feeding frenzies. Unfortunately, this has little to do with reality: the Redbellied Piranha is probably only second to Goldfish for most abused aquarium fish in the world. People are often attracted to the Piranha soley because of their legendary feeding habits, which is unfortunate, as the fish will almost certainly not live up to the high expectations. Sadly enough, this lack of knowledge and understanding often results in poor care or even negligence.
So despite its fearsome reputation, the Red Bellied Piranha has a relatively nervous and shy character (even more so than the other species of true piranha from the genus Pygocentrus). This is due to the fact that in the wild many species of predator prey on the Redbellied Piranha: a Piranha has to be on constant alert to avoid being killed by an animal that takes up a higher place in the food chain, or even its own kind. Although it can, and often over time will adjust to the presence of humans nearby, many captive reds will remain skittish throughout their life. Keeping them in a shoal of at least 5 fish (the more, the better), dimming the lights and using blackwater extract to mimic the murky waters of their original habitat, providing adequate places for them to hide (rocks, bog wood, plants), raising the water temperature, adding a potent powerhead to the tank, and placing the tank in a high traffic area are all suggested as the solution to decrease skittishness, but unfortunately there is no guarantee any of these measures will work: shyness and wariness are part of the nature of the beast, and that is hard to change.

A final warning: in captivity this species may appear timid and shy, but keep in mind that underestimating what these animals are capable of can have severe consequences. A cornered or threatened piranha will not hesitate to bite, and an adult specimen can remove a finger with ease.

!!! So treat these animals with the utmost respect at any time !!!

Some pictures of Pygocentrus nattereri

Baby P. nattereri
Baby P. nattereri
Photo by: Redpred

Juvenile redbellies
Juvenile Redbellied
Photo by: Jonas Hansel

Sub-adult redbellied piranha
Sub-adult redbellied piranha
Photo by: Bob Hare

Darkly colored adult P. nattereri
Darkly colored adult P. nattereri
Photo by: Jonas Hansel

Pygocentrus nattereri var. 'Ternetzi'
Pygocentrus nattereri var. 'Ternetzi', the yellowbellied variant
from Paraguay, Argentina and Southern Brasil.
Photo by: William's
Piranha-Fury NL

Pygocentrus nattereri var. 'Super Red'
Pygocentrus nattereri var. 'Super Red', a brightly colored and
remarkably patterned variant from Peru and Northern Brasil.
Photo by: Matthias19

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