The Red-bellied Piranha Pygocentrus nattereri has a long history with aquarium keepers. It has been kept by aquarists for well over 60 years. This species is also one of the most commonly found of the piranhas with a wide distribution throughout the Amazon and Orinoco Basins in South America. The members of the Pygocentrus genus are considered the "true piranhas", and this fish is perhaps the most handsome looking of the piranha group.
The Red Belly Piranha is gorgeous in its adult coloring. Its back is a steel gray, and the rest of the body a silvery gold with a bright orangish-red to red throat, belly and anal fin. It is one of the larger piranha species, reaching up to 13 inches (33 cm), though smaller in the aquarium. In the wild they are found in groups of about 20 or so fish. These shoals provides a pack for hunting but also provides individuals protection from predators. This species is considered to be one of the most ferocious of the piranha predators.
These Piranhas are not picky eaters and are quite hardy, but are best kept by more experienced fish keepers. As a pet the Red-bellied Piranhas make fascinating and beautiful fish, yet you can't hold or pet them. They are not affectionate and owners must be extremely careful, especially when handling them. They do have sharp teeth and an aggressive/defensive nature. Most Piranha bites are sustained when the fish are being handled, though that's not to say a hungry fish is never dangerous.
The Red-bellied Piranha are highly predacious and definitely not a candidate for a community tank. They can be kept singly, but are actually one of the easier piranha species to keep in a group. They can be combined with other Pygocentrus species as well as other Red Piranhas. In a group, some of their natural behaviors will show if they are kept under proper conditions. However even in an established group, the potential for aggression and cannibalism amongst piranhas is not unusual. Generally the largest, most aggressive fish will be dominant. It will demand the best spots in the tank and be the first to feed. Any perceived competition by another fish will be quickly corrected with aggressive behavior of chasing and even inflicting wounds.
For a single fish, a minimum sized tank of 40 gallons is needed, but keeping a group will require a much larger aquarium. They are also big, messy feeders so need ample filtration and regular water changes to handle the bio load feeding puts on the tank. They are generally less skittish and shy when they live in a tank with plenty of hiding places and dimmed lights. Keeping them in a school of 4 or more will also help overcome their timidity.
The Red-bellied Piranha Pygocentrus nattereri (previously Serrasalmus nattereri and Rooseveltiella nattereri) was described by Kner in1858. There is much discussion and debate on the true taxonomy of this fish, so its scientific name may change in the future, but currently it is considered P. nattereri. The species is not listed on the IUCN Red List. Other common names this species is known by are Red Belly Piranha, Red Piranha, and Natterer's Piranha. A few variants in color have also led to occasional use of such names as Ternetzi Piranha, Super Red Piranha, Snakeskin Piranha, and Gold-dust Piranha.
Red Belly Piranha are found across a wide geographical range in South America, including Venezuela, Brazil, Peru, Guyana, Bolivia, Paraguay, Argentina, Colombia, Ecuador, and Uruguay. They live in the Amazon River Basin as well as the basins of the Paraguay, Paraná, and Essequibo Rivers, in coastal rivers of northeastern Brazil and numerous other small water systems.
They inhabit all sizes of running waters from rivers, to tributaries and creeks. They also are found in larger bodies of water including lakes, pools, flooded forests, and the Pantanal wetlands of southwestern Brazil. They are one of the schooling piranha, and are generally found in groups of 20 to 30.
They are an opportunistic omnivore with a widely varied diet that includes fish, both whole and in pieces, fish fins and scales, insects, snails, and plants. Besides being scavengers, if necessary they are full blown predators as well, and will actively give chase to their prey.
Scientific Name: Pygocentrus nattereri
Social Grouping: Groups - Generally found in schools of 20 to 30 fish.
IUCN Red List: NE - Not Evaluated or not listed
The Red-bellied Piranha can get up to get up to 13 inches (33 cm) in length in the wild, though in captivity they are generally smaller. A lifespan of 10 years is normal, but there are a few where they have lived for over 20 years.
They have a powerful, high, thick but laterally compressed body shape. Like all piranhas they have a keel-like edge running along the upper part of the body from head to dorsal fin, and on the lower body running over the belly. Members from the genus Pygocentrus are all recognizable by the convex shape of their head and massive bulldog-like lower jaw. Together with a powerful large tail and a body covered with very small scales, their streamlined bodies make them very fast and agile swimmers. They also have a small adipose fin between tail and dorsal fin, a characteristic of all the Characins.
The Red Belly Piranha is gorgeous in its adult coloring. Body colors can be variable, but mostly the back is a steel gray and the rest of the body is a silvery gold with a bright orangish-red or red colored throat, belly and anal fin. It has large black spots on the sides and sparkles with many shiny scales. Some have such intensely gold-speckling that they are sometimes called a Gold-dust Piranha. There is also a yellow bellied color variation. In its juvenile form, it is more silver colored with dark spots.
Size of fish - inches: 13.0 inches (33.02 cm) - These fish get up 13 inches (33 cm) in the wild, but are usually smaller in captivity.
Lifespan: 20 years - Generally have a lifespan of about 10 years in captivity, but have been known to live for over 20 years.
Fish Keeping Difficulty
Red Belly Piranhas are not picky eaters and are quite hardy. However they are predacious fish and are best kept by more experienced fish keepers. You can't hold or pet them, and they are not affectionate. Owners must be extremely careful, especially when handling them.
Aquarium Hardiness: Moderately Difficult - Although these fish are fairly hardy, aggression often leads to injury which can shorten the lifespan of this fish in the home aquarium.
Aquarist Experience Level: Advanced - Owners must be extremely careful, especially when handling them.
Foods and Feeding
The Red-bellied Piranhas are carnivorous omnivores. In the wild their diet is widely variable, including fish, both whole and in pieces, fish fins and scales, insects, snails, and plants. In captivity they can be trained to eat whole dead fish, such as frozen silversides and lancefish, as well as a variety of other meaty foods such as prawn, mussels, and fish flesh. They will eat live foods such as feeder fish, earthworms, and river shrimps, but this is not really desirable as it puts a huge pollution load on the aquarium.
Diet Type: Omnivore
Flake Food: No
Tablet Pellet: No
Live foods (fishes, shrimps, worms): Some of Diet
Vegetable Food: Some of Diet
Meaty Food: Most of Diet
Feeding Frequency: Daily
Red-bellied Piranhas are big messy feeders, so need ample filtration and regular water changes to handle the bio load. Water changes of 30 - 50% every other week are recommended.
Water Changes: Bi-weekly - Do a 30 - 50% water change every other week.
The Red Belly Piranha will swim in all parts of the aquarium, An aquarium or 40 gallons is minimum for keeping a single specimen, but keeping a group will require a much bigger tank. They are apprehensive fish, and keeping them in a school of 4 or more will help overcome their timidity. Because they are very messy feeders, they need strong filtration to keep up with the bio load and a moderate water flow.
These are rather timid fish but will tend to be less skittish and shy in an aquarium with plenty of hiding places. However they also need plenty of swimming space. This species is an omnivore, and has been reported to eat some aquarium plants. However, adding bog wood and placing plants around the perimeter, will offer some cover to help them feel at home and still provide an open area for swimming. Provide a substrate of sand or fine gravel and lighting that is dim.
Minimum Tank Size: 40 gal (151 L) - A 40 gallon aquarium is fine for a single fish, but a group will need an aquarium of 100 gallons or more.
Suitable for Nano Tank: No
Substrate Type: Small Gravel
Lighting Needs: Low - subdued lighting
Temperature: 74.0 to 82.0° F (23.3 to 27.8° C)
Range ph: 6.5-7.5
Hardness Range: 4 - 18 dGH
Water Movement: Moderate
Water Region: All - These fish will swim in all parts of the tank.
In the wild the Red-bellied Piranha swims in schools, usually of 20 to 30 fish. They are ferocious predators and definitely not a candidate for a community aquarium. They can be kept as a single specimen, but are actually one of the easier piranha species to keep in a group. They can be combined with other Pygocentrus species as well as other Red Piranhas.
A group should be a school of at least four or more. Yet even in an established group there is the potential for aggression and cannibalism amongst piranhas is not unusual. Generally the largest and most aggressive fish will become dominant. This fish will claim the best spots in the tank and be the first to feed. A challenge by another fish will result in aggressive behavior of chasing and even inflicting wounds.
Temperament: Aggressive - This fish sometimes appears suprisingly skitish in the home aquarium. A school of piranha is incredibly hierarchal and there will be a clear chain of command. Although the sturdiest of tankmates may survive alongside this species, it is probably best to just go for a species tank.
Same species - conspecifics: Yes - This fish can be kept as a single specimen, or in a group of at least four, or more of its own kind or other Pygocentrus species.
Peaceful fish (): Threat
Semi-Aggressive (): Threat
Aggressive (): Threat
Large Semi-Aggressive (): Threat
Large Aggressive, Predatory (): Threat
Slow Swimmers & Eaters (): Threat
Shrimps, Crabs, Snails: Threat - is aggressive
Plants: Monitor - They have been reported to eat some aquarium plants.
Sex: Sexual differences
This species is not sexually dimorphic. Visual differences between the sexes may possibly be determined if the fish are observed over a long period of time, including pre-spawning activity. However any color variation is limited to the female being full of roe and the male being in pre-spawning colors. At this time the male will be a more silvery gold while the female will have more yellow.
Breeding / Reproduction
The Red-bellied Piranha has been bred in home aquariums. It should be noted that breeding this fish is difficult and an optimal process for doing so is not well established. Also because this is a very complex species, the results can have many variations of spotting, body shape and coloration.
To breed, the aquarium needs to be quite large, at least a 6 feet in length and 24 inches wide. The first challenge is finding a suitable breeding pair. Sexing is unreliable, although the thickness of the fish has been suggested to indicate gender. A school of at least 6 fish will be needed to have a pair form.
In the wild, spawning usually takes place in the wet season during the months of April and May. Frequent, large water changes should induce breeding as these fish believe the rainy season has begun. A pair will darken in color, separate from the group, and dig a bowl shaped spawning pit. The pit will be about 1 1/2 to 2 inches (4 - 5 cm) deep and about 6 inches (15 cm) across.
Do not disturb them during spawning. Spawning takes place with a courtship ritual of swimming in circles and then a ventral-to-ventral interaction. This will induce the female to lay the eggs in the sediment of the pit and they are fertilized by the surrounding water. The female will then swim away and the male will guard the nest. In the wild the eggs are in clusters and are attached to the bottom vegetation.
The eggs should be raised in a separate tank. Each spawn can produce hundreds of fry. Once the fry are free swimming they can be fed newly hatched brine shrimp. In nature they feed on macroscopic plant life. The fry are cannibalistic, so the larger fry will eat smaller siblings.
Ease of Breeding: Difficult
The Red-bellied Piranha fish are hardy and disease is not usually a problem in a well maintained aquarium. That being said there is no guarantee that you won't have to deal with health problems or disease. Anything you add to your tank can bring disease to your tank. Not only other fish but plants, substrate, and decorations can harbor bacteria. Take great care and make sure to properly clean or quarantine anything that you add to an established tank so not to upset the balance. If you feed any live fish, disease can be passed to them from their foods. Make sure to quarantine live food before feeding. These fish are also at risk for getting wounds inflicted by tank mates. These can lead to contracting bacterial and other infections.
A good thing about the Red Belly Piranha is that due to their resilience, an outbreak of disease can often be limited to just one or a few fishes if you deal with it at an early stage. The best way to proactively prevent disease is to give your fish the proper environment and give them a well balanced diet. The closer to their natural habitat the less stress the fish will have, making them healthier and happy. A stressed fish is more likely to acquire disease.
As with most fish the Red Piranha are prone to skin flukes, parasitic infestations (protozoa, worms, etc.), ichthyobodo infection, parasitic infestations (protozoa, worms, etc.), bacterial infections (general), and bacterial disease. They are additionally prone to wounds from attacks by tankmates, which can then lead to bacterial or fungal infections. It is recommended to read up on the common tank diseases. Knowing the signs and catching and treating them early makes a huge difference. For information about freshwater fish diseases and illnesses, see Aquarium Fish Diseases and Treatments.
The Red-bellied Piranha is the most common piranha found for sale in U.S. However, these fish have provoked fear in conservationists and the media and have been irresponsibly released into many waterways. Consequently, although they are readily available for sale, they are no longer legal to keep in all states. Before purchasing these fish, be sure to check with the authorities in your area to find out if you can keep them.
bassam ronz - 2013-05-16 Hiii every one i have 6 oscars cichlids i albino and 5 tiger with 1 recently baught jack dempsy. Any one knows if i could buy pirhana in this tamk it is 2 meters length and 50 width and 50 higth it is a very big tank
Jeremy Roche - 2013-05-16 I would not recommend this! Pirhana are usually species only fish.
prescott - 2012-12-12 I have a red belly pirahna and in the last few months, its stomach has gotten quit large, does not look normal, in the last few weeks it seems to be bigger on one side, could it be pregnant? Or some type of disease, plz help
Jeremy Roche - 2012-12-13 Curious, what are you feeding the fish? Any beef products or dog foods?
Pete Mclean - 2012-10-31 He he I got a red belly pirahna called Bob had him for almost 6 years now and yeah he skittish lives in a 4 ft tank with a large plec not sure who is more aggressive though the pirahna or the plec but Bob now comes and takes food from my hand. He's the best fish I have kept so far always up to something whether it be trying to hide behind a twig or attack me while I am walking past would recomend red bellies to anyone who has time to watch them :D
Jeremy Roche - 2012-10-31 Pirahna make interesting pets, but they are not for everyone. Experienced owners are a must.
Adam - 2012-10-30 I have a 55 gallon tank and I want aggressive fish. Are Piranha and Pacus basically the same and can live together.
Jeremy Roche - 2012-10-30 These fish are from the same family, but are very different. They do however look a bit similar but that is as far as it goes! The Pacu grows faster and normally larger in aquariums and is not as aggressive. They can be very aggressive to smaller fish. They will eat vegetables as well meat. Much easier fish to keep, but a 55 Gallon tank will be too small for a for a forever tank.