Red-bellied Piranha

Pygocentrus nattereri

An Amazon fish with a red belly and sharp teeth that often nips fins from bigger fish and helps clean up rivers.

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About the Red-bellied Piranha

Red-bellied piranhas grow a little over a foot long and up to 4 pounds. They are gray with sparkly silver scales and red bellies. They live in still and moving fresh waters of the Amazon basin and travel in schools of 20 or more. Much of their diet is fins nipped from bigger fish, plus bits of flesh, small fish, insects and sometimes ripe fruit.^[1]

Quick facts

Scientific name: Pygocentrus nattereri^[1]
Size: A little over 1 foot long.^[1]
Weight: Up to 4 pounds.^[1]
Lifespan: 10 years or more.^[1]
Diet: Fins of bigger fish, bits of flesh, small fish, insects and some fruit.^[1]
Habitat: Still and moving fresh water.^[1]
Where it lives: Low-elevation areas of the Amazon River basin.^[1]
Group life: Schools of 20 or more.^[1]
Babies: Eggs attached to underwater plants in a nest the male digs.^[1]
Conservation status: Least Concern (IUCN Red List, assessed 2020).^[2]

Fun facts

Much of a piranha's diet is fins nipped from bigger fish.^[1]
Piranhas sometimes eat figs and other fruit.^[1]
Courting piranhas swim in circles.^[1]

Vocabulary

fish: A cold-blooded animal that lives in water, breathes with gills and usually has fins and scales.
scavenger: An animal that eats dead plants or animals it finds.
school: A group of fish swimming together.
freshwater: Water that is not salty, like most rivers and lakes.
least concern: A conservation label meaning a species is widespread and not at risk of dying out soon.

See it in person

Smithsonian's National ZooWashington, D.C. · AmazoniaSee this animal on the zoo's website ↗

These zoos had this animal when we gathered our information, but animals sometimes move. Check the zoo's website or contact the zoo before you visit.

Sources

[1] Smithsonian's National Zoo & Conservation Biology Institute. “Red-bellied piranha.” https://nationalzoo.si.edu/animals/red-bellied-piranha (accessed 2026-10-08)
[2] IUCN Red List of Threatened Species. “Pygocentrus nattereri (Red-bellied Piranha).” https://www.iucnredlist.org/species/186604/1815617 (accessed 2026-10-08)

Facts last checked 2026-10-08.

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