Piranha - Pygocentrus nattereri

Updated May 14, 2020
Author: Mike - FishLore Admin
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The Piranha is an infamous fish known for its meat eating capabilities and although it is an extremely interesting fish, we do not recommend them for the beginner. They can get quite large and expensive to feed. I also wouldn't want to put my hand in a tank full of them while performing tank maintenance. Yikes!

Pygocentrus nattereri School of Piranha

Use caution if you plan to feed them a steady diet of feeder guppies or feeder goldfish since these may introduce many different diseases to your tank. Try to get them on flakes or pellets as soon as possible and only give them live foods as a supplement to their diet.

Pygocentrus nattereri

Piranha head and mouth view

They will do better when kept in a school and given that information, you will need a larger tank to keep them long term. A large and over-sized aquarium filter (canister filter) will help as well since they can be somewhat messy eaters.

See the Piranha Care Sheet on the forum for more details on keeping them.

Piranha School Pygocentrus nattereri


Piranha Fish Care Details

Scientific Name : Pygocentrus nattereri

Common Names : Red Belly

Care Level : Moderate

Size : Up to 12 inches (30 cm)

pH : 6 - 7.5

Temperature : 73°F - 82°F (23°C - 28°C)

Water Hardness : 10° to 20° dH,

Lifespan : 8 - 10 years

Origin / Habitat : South America

Temperament / Behavior : A very peaceful fish - just kidding. This is a very aggressive and a very dangerous fish. You need a larger tank for them. They will eat your smaller fish. There have been studies done showing how introducing them into a non-native waterway can significantly impact the native fauna and fish species. I would hope this would go without saying, but please don't release captive raised aquarium species into your local water ways.

As climate change and global warming march on, their over winter survival rates will continue to increase which will lead to more piranhas over larger areas.

Breeding : Extremely difficult.

Aquarium Size : 55 gallon minimum, even though you see them (juveniles) in 10 gallon pet shop tanks. If you keep them in a smaller tank be prepared to perform more frequent aquarium maintenance.

Tank Mates : Not many - mainly other Piranhas

Fish Disease : Freshwater Fish Disease - Diagnose, Symptoms and Treatment

Food : Omnivore - feeding them can become fairly expensive because they prefer live foods. Try to give them flakes and pellet food for their primary nutritional needs and supplement with live foods.

Tank Region : Middle

Gender : Difficult to determine but the female may be larger and have more yellow in them. We've also read reports that suggest that the female may become darker around spawning time.

Photo Credit : Photos copyright JJPhoto.dk

References :

Fish Lore Forum : Piranha Forum

Pygocentrus nattereri Pygocentrus nattereri

Piranha Comments and Tips

From: Keiland
I think I have five of these and I want to be sure. What is the easiest way to differntiate them from Pacus? They are rather small, about two inches.
They do look very similar to the pacu at a young age. The easiest way to tell would be the shape of the lower jaw. On the piranha the lower jaw sticks out more. You should also be able to see the teeth better on piranhas at the size you have.

From: Joe
I have 6 in a species only 55 gallon tank. They are getting very big and it is getting expensive to feed these fish!
Yeah, it can get expensive. Are you only feeding them live foods (feeder goldfish)? You could try to give them mostly pellet or flake foods and just supplement their diet with the feeder fish.

From: James
Please don't crowd them into small tanks. These guys can get extremely messy and need larger tanks with frequent water changes.

From: Sandy
Live food can intoduce disease especially if you just buy and feed it to the fish. My husband breeds his own.

From: Jim
I had 4 red bellies in a 75 gallon tank. I'm no expert and don't know if it's healthy, but I was feeding them jumbo shrimp that I bought in the frozen food section. A big bag for around 5 dollars and they love them.

From: Iwan
I have 10 red belly, give them pellets and sometimes goldfish. In Indonesia they are only 40 cents for 1, 5 inch fish. They seem to be growing 1 inch every few weeks.

From: Joshy
Red Bellies need 20 gallons each - Minimum! And no less than 4 should be housed together, as they school and take agression out on each other. Do lots of research before buying!

From: Mark Kubal
I have had 5 red bellies in a 90 gallon tank for 11 years now. They are very easy to take care of but a tad messy at dinner time which requires more intervals of clean-up time. I find them extremely loyal when I clean the tank. They like to eat when the room is empty without distraction.

From: Soopamegan
This says that they are carnivores, but they are actually omnivores. In fact, the Indians in the Amazon know when it is safe to bathe in the river when fruits are falling from the trees into the water. They just go up river and swim because they actually prefer the fruit to meat.

Mine (and pacus, and oscars, though I keep none of these in the same tanks) all seem to like citrus fruits and squash really well as a supplement to their diet.

From: Lisa
I have a red bellied piranha that is now approx. 4 inches. He was at most 3/4" when I first got him, about 3 months ago. I take a picture once a month to show rate of growth. He is in a 55 gallon tank with no lighting, just natural light from across room. Tank is kept at 82 degrees. I have taught him that in order to eat he must come to a certain area of the tank. He never hides and follows us back and forth. The dogs to! I have no mess from food because I break off mouth size pieces of whatever meal and feed one at a time till he is full. He is still getting 3 meals a day. He gets salmon, shrimp, prawn, mealworms, earthworms, scallops, sole and any other white meat fish I can think of. Tuna too. I get everything from the sea food section of our food store. I make sure everything has been previously frozen to avoid any diseases. The prawn I get from the petstore. He lives with my 8 inch pleco peacefully (so far).

From: AC
In India, we face no problems getting piranhas. We have one dozen red bellies in a 5X2 feet, that is 650 liters of water in the aquarium. They are eating only Goat mutton. Occasionally we introduce beef but they liked to eat goat. The fish are very shy. Sometimes they strike the water with violent force. We are fascinated by stories of their carnivorous nature. Astonishingly, I found these are comparable with any other fish regarding discipline. Any one can easily adopt this fish if they have a big tank and enthusiasm.

From: AKG
I have 6 Red Belly in a 100 gallon tank, the largest one is around 10". They are aggressive only during feeding time and if they see a new fish being introduced (which is devoured in a couple of hours). Otherwise, they are very skittish and freak out very easily. They don't like bright lights and are very active when the room is dark and empty. They require a lot of water changes, as I feed them meat / fish 2-3 times a week. Mine are pretty large and will not recognise pellets or flakes as food anymore. The only fish that has survived with them is a medium sized common pleco, all others have become meals for the piranhas. A very interesting and rewarding fish to have!

From: Lisa
I have to disagree with some of the info given above. The piranha is not a VERY dangerous fish. It just takes common sense when caring for one. My hands are in the tank alot. I just always feed previously. They want to avoid you. They will bite if scared or starving. Also, they can be bred in captivity. And, as far as feeding goes, flakes and pellets should NOT be their primary source of nutrition. It is a great supplemental food. But they shoud get variety, white fish meats, worms, etc. I also meant to add, live foods shoud be quarantined due to diseases. Gold fish are also growth inhibiting.

From: Brandon
I have 4 red bellies, they are in a 55 gallon tank with a bottom feeder and about 20 small gold fish at a time. I have an extra large filter to keep up with their eating. They are all about 6-7 inches long and are very aggressive and they don't bite my hand but they eat what ever they can. They are only about 4 or 5 months old and I love having them. I also keep a tiger osar in the tank with them and they get along like brothers, never had any trouble.

From: Adam
I have two juvenile red bellies in a 30 gallon that are growing very nicely! Black and white gravel really compliments their color. No doubt about feeding them live fish only as a treat, because that can become expensive. Test that pH often.

From: Eric Schuh
I have six red-bellied piranhas in a 55 gallon tank and they get along well with the red-tailed shark. We feed ours about 1 goldfish each, every 2-3 days. I heard that feeder goldfish are not good for them. Is this true? If it is what else can I feed them?
The feeder goldfish can bring in disease if they are not put into a quarantine tank and monitored for several weeks before feeding them to your fish. Too much of the same thing for every meal is not a good thing for most species. Try to vary their diet with a high quality pellet food and supplement (feed less often) with the live foods.

From: Rajesh Plakkat
Keep small feeder fish like small gold fishes or guppies in large numbers to minimize agression among piranhas cause they always keep an eye on other tiny other fishes which they can't catch easily. Give them shade by placing wood pieces or stones so they can have more places to hide.

Still have questions?
Jump on the forum and ask your question!
Go here: Piranha Forum

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