Although piranha fish are only about 12 inches long, some of them are vicious predators and, therefore, an object of fascination for kids. If your kids are curious about these fish and have a steady stream of questions concerning them, be ready with informative and accurate answers. You might even offer some additional facts about piranhas that might further pique your children's interests and curiosities. For starters, you can tell them that red-bellied piranhas gnaw on the fins and flesh of nearby fish even when they are mere babies at just 1.5 inches in length. They don't mind eating their prey alive either -- and adult piranhas sometimes eat their own babies. Incredibly, hungry piranhas might even attack humans.
You'll likely want to explain to your kids a little about why and how piranhas go in for the kill. Tell them that certain piranhas have killer instincts, aggressive natures and razor-sharp teeth -- so sharp that South American fishermen use their teeth to make tools and weapons. Some piranhas have a powerful lower jaw that can cause serious injury or death to larger animals. Explain that a young fish of 6 inches in length has teeth that are 1/6 of an inch long and already razor-sharp. Also note that just like sharks, piranhas can locate their prey with an extraordinary sense of smell.
You'll also want to explain to your kids that not all piranhas are killers. Freshwater piranhas are native to South America and live in lagoons, rivers and lakes. There are approximately 20 species of piranha living in the Amazon River, while only four or five of them are dangerous -- the red-bellied ones are among the most dangerous species. Tell your children that the non-dangerous ones are docile and harmless scavengers. Some feed on leftover fish scraps, while vegetarian piranhas eat fruits and seeds.
Not Good as Pets
In case your children ask you for a pet piranha, it helps to know that while the U.S. Fish and Wildlife Service does not require a permit for owning a piranha, individual states have their own laws, as enforced by fisheries managers and natural resource police. This is because in the past, piranha owners gave up on keeping them as pets and released them into local bodies of water. Releasing dangerous piranhas poses a risk to fish and humans. According to the Extreme Science website, piranhas aren't good pets in the traditional sense because you can't hold or pet them, they aren't affectionate -- and they have sharp teeth.
You might want to discuss prehistoric piranhas with your kids, noting that if today's red-bellied piranha isn't fierce enough, imagine the ancient carnivorous mega-piranha that lived millions of years ago. The force of its bite was 50 times its weight, according to LiveScience.com. This 20- to 30-pound fish lived in South America during the Miocene era. Scientists think that these monsters went extinct when the Andes Mountains rose and separated the Amazon and Parana basin into two basins. Smaller piranhas like the ones we know today in South America took their place.