Aquarium Fish

Piranha Fish

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!

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.

They will do better when kept in groups 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.


Red Belly Variety Piranha
Pictures courtesy of Andreas Sunarso


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.

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.

References :

Fish Lore Forum : Piranha Forum


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.

More Tips and comments.

More Tetra Fish Profiles

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These tetras have red heads that can change colors depending on environmental stressors.

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