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Today on Animal Fact Files we’re talking about piranhas. These fish have a bad rep which may go back more than 100 years ago when Theodore Roosevelt described them as: “ferocious creatures” “blood crazy fish” “the embodiment of evil ferocity”. Well, who’s going to contest the 26th president of the United States? Actually, we are. Piranhas really aren’t the crazy killers portrayed in the media. There isn’t a single documented case of a piranha killing a human, and attacks on people are rare. Even children swim in the same waters piranhas inhabit.

Piranhas live in South America. Their classification is currently all over the place with some sources says they are fewer than 30 species and others saying there are more than 60, but the point is that there are multiple piranha species, they aren’t just one type of fish. Piranhas enjoy fast moving rivers and streams but are also found in slower water systems, lakes, and flooded forests. During the dry season they become more vulnerable to attacks from birds because waterways may dry up leaving the fish exposed in shallow water. Piranhas are also taken by larger fish, caiman, turtles, and freshwater dolphins - they’re not considered apex predators. In fact, the groups piranhas form, originally believed to be for hunting, are more likely for safety purposes. The phrase “safety in numbers” specifically applies here.

When piranhas do take prey, they do so opportunistically, and some species are mostly vegetarian! Piranhas will eat smaller fish, crustaceans, insects, frogs, seeds, fruits, and just about anything else edible that falls into the water. They’ll also take bites out of larger fish, nibbling on a fin or loose scale. Piranhas themselves don’t grow larger than two feet (61 centimeters), the average piranha being half that or smaller. They also weigh on average about half of what Chester weighs.

Piranhas recognize the splash of falling fruit as the potential for a meal, so they’ll head to disturbances in the water. This is why piranhas may also eat large mammals. If an injured animal is splashing around, it may attract the attention of a group of piranhas, but they can’t strip an animal to its bones in seconds like movies might have viewers believe. In fact, piranha “feeding frenzies” are more orderly than the average potluck. If a group of piranhas has opportunistically found a larger meal, they will swim around it, each taking a bite and swimming out of the way so the next fish in line can have its turn.

Piranha teeth are amazing, and not just for their scissor-like power - though they do come together and can slice just like scissors! Their teeth look kind of like shark teeth, but they are interlocked so they don’t lose individual teeth the way sharks do. Instead, piranhas lose an entire row of teeth all at once which is quickly replaced by another entire row. This may happen upwards of 30 times in piranha’s lifetime, which may last up to eight years.

Piranhas eggs are laid in bowl shaped nests in the riverbed. The eggs cluster together after fertilization and attach to vegetation. A few days later, they’ll hatch and the babies are on their own. They’ll learn tactics to try and intimidate predators such as making noises with their swim bladders and gnashing their teeth, but at end of day, they aren’t nearly as terrifying as they’re made out to be.

For more facts on piranhas check out the links in the description. Give a thumbs up if you learned something new today, and thank you for watching Animal Fact Files.