Fun Piranha Fish Facts For Kids

Moumita Dutta
Oct 31, 2022 By Moumita Dutta
Originally Published on Aug 18, 2021
Edited by Monisha Kochhar
Piranha fish facts are educational!

Piranhas are omnivorous fish found mainly in the South American ecosystem. Out of 60 species of piranhas, more than 25 are found in the rivers of the Amazon basin.

Piranhas have razor-sharp teeth with strong jaws that function like scissors and are predatory fish found living in rivers, creeks, or wetlands. Most species of piranhas are scavengers and will prey on insects, smaller crustaceans, plants, and seeds.

The most notorious of the piranha species are the black piranhas and the red-bellied piranha as they are known to be aggressive towards humans and other animals.

The red-bellied piranha (Pygocentrus nattereri) which has the sharpest teeth in the piranha species is commonly found across the world as they are sold as exotic pets in regions where they are legal. It is illegal in many parts of the United States and the Philippines to have piranhas as pets.

If you like these facts about the piranha then visit porbeagle shark facts and skate fish facts too!

Piranha Fish Interesting Facts

What type of animal is a Piranha Fish?

Piranha, also known as piraya, is an omnivorous fish with razor-sharp teeth.

What class of animal does a Piranha Fish belong to?

Piranhas belong to the Actinopterygii class of fish. The ray-finned fishes are named so because their fins are web-like with support by bony or horny spines.

These fin rays are directly attached to the basal skeletal elements, which helps in representing the connection between the fins and the internal skeleton. Actinopterygians are known to be the dominant class in the vertebrates and comprise nearly 99% of over 30,000 fish species.

How many Piranha Fish are there in the world?

An accurate number of the piranha population is hard to pinpoint. The piranha species stand at an estimated number of fewer than 30 and more than 60. The most commonly known species of the piranhas are the Red-Bellied Piranhas, scientific name Pygocentrus nattereri.

Where does a Piranha Fish live?

Piranhas are found in most freshwater bodies in South America. Piranhas can survive in any of the South American rivers, creeks, lakes, or wetlands.

What is a Piranha Fish's habitat?

Piranhas inhabit the freshwater bodies of South America ranging from the Orinoco River Basin in Venezuela up to the Parana River in Argentina. An estimated 30 species of piranhas live in the rivers and lakes of South America today.

Since the Amazon rainforest is surrounded by dense vegetation which causes the creation of canopies that block light from reaching the water surface and in turn becomes a great hiding spot for piranhas to be safe from predators like crocodiles, dolphins, and birds.

Who do Piranha Fish live with?

Piranhas live in groups called a shoal. This group mentality does not exist solely for hunting purposes, the main reason why piranhas live in groups is for safety and protection.

In cases where there is a size difference in the piranhas, they might pick on each other, bully, and end up cannibalizing each other. Red-bellied piranhas are one of the few species known to school successfully for the entirety of their lifespan.

How long does a Piranha Fish live?

Piranhas can live as long as 10-12 years in the wild, and in captivity, these species have a shorter life. The red-bellied piranha, the most common species to be sold as pets, can live up to eight years.

How do they reproduce?

Research on the red-bellied piranha has helped us in understanding the mating process of piranhas. Female piranhas lay eggs near water plants, to which the eggs stick.

The nests are about 4-5 cm deep. The male piranhas then fertilize those eggs which hatch after two to three days. The juvenile piranhas rely on a sac of yolk for nutrition during the first few days and hide in the plants till they are grown up enough to defend themselves.

Piranhas have two annual reproductive seasons, the conditions to which are tied to the fluctuations in water level, temperature, and other hydrological conditions. The individuals that are ready to mate seek habitats like marginal grasses and lakes within vegetation. The ones that are non-reproductive prefer open water and under floating meadows.

What is their conservation status?

Piranhas are currently not listed by the IUCN Red List, and their most likely conservation status is of the Least Concern. As these fish can be found throughout the South American continent, especially in the Amazon River Basin where more than 25 species directly come from.

With the introduction of the red-bellied piranha (Pygocentrus nattereri) as an aquarium fish for pet lovers all over the world, the number of red-bellied piranhas has increased at a massive rate with breeders adding to the number of the population.

But sadly, in cases of them being found in lakes and rivers outside of their native South America, they are killed by injecting the chemical rotenone into the water bodies.

Piranha Fish Fun Facts

What do Piranha Fish look like?

Piranhas have deep bodies with large blunt heads with strong jaws and razor-sharp teeth that form a triangular scissor-like bite. Most of the piranha species never grow more than 60 cm long.

Body size and color pattern can range from silvery with an orange underside to completely black, depending on the different species and on the geographic location they are born into.

Fun facts about piranhas are interesting!

How cute are they?

Piranhas, especially the red-bellied piranha, are not the best-looking fish. In the wild, they just seem weird to look at and usually scary looking, and in an aquarium, they are more intriguing than cute.

How do they communicate?

Piranhas communicate acoustically. They are known to produce short percussive drum-like sounds when they are fighting for food or circling an opponent. Softer croaks are produced by the jaws when they snap at each other. When trying to chase away predators, they emit a barking sound that serves as a warning to the predators to leave them alone.

How big is a Piranha Fish?

Most species of piranhas hardly grow any larger than 4.7-13.8 in (12-35 cm). Pygocentrus nattereri, the red-bellied piranha, has the strongest jaw in comparison to the rest of the species and can grow as long as 19.7 in (50 cm) in length.

How fast can a Piranha Fish swim?

The recorded speed of piranhas is 15-25 mph (24.1-40.2 kph) depending on the different species. A black piranha can swim at up to 25 mph (40.2 kph) whereas the red-bellied piranha, the largest of the lot, will be slower.  

How much does a Piranha Fish weigh?

There is a great deal of variability in the weight of piranhas depending on their species or habitat. A very big piranha might weigh around 11 lb (5 kg) and the red-bellied piranha in aquariums might weigh 5.5 lb (2.5 kg).

What are their male and female names of the species?

There is no particular name defined for the male and female piranhas.

What would you call a baby Piranha Fish?

Newly hatched baby piranhas are called fry.

What do they eat?

Piranhas have a diet that comprises insects, fish, worms, smaller crustaceans, seeds, and other plants. The red-bellied piranhas are known to eat about one-eighth of their body mass per day.

In cases of shortage of food, there are cases of cannibalism (living or dead). If a larger animal has fallen into the water, piranhas will eat them, as they feed in large groups. Such feeding frenzies are rare, though disturbing to witness!

Are they dangerous?

Out of the 60 or so species of piranhas, the red-bellied piranha and black piranhas are the most aggressive and dangerous towards humans and other animals.

Swimmers can navigate piranha-infested waters without being attacked, but the danger lies in the low water level, where there is a scarcity of prey and the fish are either hungry or threatened which results in them acting aggressively and attacking humans. If they do bite you, they will go for the toes or feet.

A group of 300-500 piranhas can strip down the flesh of a 180 lb (82 kg) human in just five minutes!

Would they make a good pet?

The red-bellied piranha is the most common species of piranhas kept as pets. Piranhas are reserved and hide when they sense any presence outside the piranha fish tanks.

They can get boring at times since they do not like to do activities. If kept in a large number in a single aquarium, the bigger piranha attacks the smaller ones and might end up cannibalizing them. So, they are not ideal aquarium fish.

Did you know...

The name 'piranha' translates to 'tooth fish' in the Tupi language of the indigenous tribe of Brazil. A piranha's mouth consists of a single row of razor-sharp teeth that are used as tools and weapons.

Piranhas will eat whatever meat comes across their path as they hunt in groups and can take down large animals. These groups can consist of as many as 1000 piranhas!

Piranhas are one of the oldest animals of the world as fossil evidence puts their ancestors in the continent's rivers back to 25 million years ago.

Piranha Fish attacks

Contrary to popular belief, piranha attacks on humans have been greatly exaggerated through movies and stories. Piranha fish attacking humans is a rare occurrence, and results only in minor injuries, mainly to the feet or hands.

There have, however, been fatal cases. In 2012, a 6-year-old Brazilian girl in Para, Brazil, died after being attacked by piranhas when her grandmother's boat capsized. It is believed the girl drowned before the piranhas got to her. And in another case, another child died after piranhas devoured the flesh on his forearm, also in Para.

Do people keep Piranha Fish?

Yes. Piranhas are found all over the world in exotic pet stores, and as pets, except in countries like the UK, where it is illegal to keep piranhas as pets without the proper paperwork.

A typical red-bellied Piranha costs $5-$20 USD, and a small school of up to 10 fishes will cost you around $80-$100 USD.

Here at Kidadl, we have carefully created lots of interesting family-friendly animal facts for everyone to discover! Learn more about some other fish including milkfish, or fluke fish.

You can even occupy yourself at home by drawing one on our Piranha coloring pages.

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Written by Moumita Dutta

Bachelor of Arts specializing in Journalism and Mass Communication, Postgraduate Diploma in Sports Management

Moumita Dutta picture

Moumita DuttaBachelor of Arts specializing in Journalism and Mass Communication, Postgraduate Diploma in Sports Management

A content writer and editor with a passion for sports, Moumita has honed her skills in producing compelling match reports and stories about sporting heroes. She holds a degree in Journalism and Mass Communication from the Indian Institute of Social Welfare and Business Management, Calcutta University, alongside a postgraduate diploma in Sports Management.

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