Piranhas are also hard to tell apart in terms of species, diet, coloration, teeth, and even geographic range. This lack of knowledge adds a bit of dark mystery to the creatures. Sure, they're not cute and cuddly. Here are 14 fun facts about the freshwater fish:. When Theodore Roosevelt journeyed to South America in , he encountered, among other exotic creatures, several different species of piranha. Even the most formidable fish, the sharks or the barracudas, usually attack things smaller than themselves.
But the piranhas habitually attack things much larger than themselves. They will snap a finger off a hand incautiously trailed in the water; they mutilate swimmers—in every river town in Paraguay there are men who have been thus mutilated; they will rend and devour alive any wounded man or beast; for blood in the water excites them to madness. They will tear wounded wild fowl to pieces; and bite off the tails of big fish as they grow exhausted when fighting after being hooked.
Roosevelt went on to recount a tale of a pack of piranhas devouring an entire cow. According to Mental Floss , locals put on a bit of a show for Roosevelt, extending a net across the river to catch piranhas before he arrived. After storing the fish in a tank without food, they tossed a dead cow into the river and released the fish, which naturally devoured the carcass.
A fish that can eat a cow makes for a great story. Though estimates vary, around 30 species inhabit the lakes and rivers of South America today. A study suggests that modern species diverged from a common ancestor around 9 million years ago. Also, the Atlantic Ocean rose around 5 million years ago, expanding into the flood plains of the Amazon and other South American rivers. The high salt environment would have been inhospitable to freshwater fish, like piranhas, but some likely escaped upriver to higher altitudes.
Genetic analysis suggests that piranhas living above meters in the Amazon have only been around for 3 million years. Piranhas attract a certain type of pet lover, and sometimes when the fish gets too large for its aquarium said pet lover decides its much better off in the local lake.
In this manner, piranhas have shown up in waterways around the globe from Great Britain to China to Texas. Piranhas are known for their razor-sharp teeth and relentless bite.
Adults have a single row of interlocking teeth lining the jaw. True piranhas have tricuspid teeth, with a more pronounced middle cuspid or crown, about 4 millimeters tall. The actual tooth enamel structure is similar to that of sharks. But, while sharks replace their teeth individually, piranhas replace teeth in quarters multiple times throughout their lifespan, which reaches up to eight years in captivity. Though they are hardly as menacing as fiction suggests, piranhas do bite with quite a bit of force.
However, not all piranha species have a taste for blood; some are vegetarian. Many different fish are called "piranha," but the number of species is a matter of debate, according to Piranha-Info. Based on current data, there are between 40 and 60 different species of piranha in 12 different scientific families. Two species, Pygocentrus and Serrasalmus , are popular as aquarium fish, according to Piranha-Info.
The most commonly known species is Pygocentrus natterei , the red-bellied piranha. Most piranhas don't get any bigger than 2 feet 60 centimeters long. For example, the red-bellied piranha and the piraya piranha grow to about 20 inches 51 cm long, while the black spot piranha grows to about 11 inches 28 cm , according to FishBase. All piranhas live in South America in rivers and lakes, and 20 different species are found in the Amazon River , according to Encyclopedia Britannica.
Some piranhas have been found around the world, but these are thought to be pets that were released into waterways. In some U. Piranhas live in groups called a shoal. It is a popular belief that these fish travel in groups so that they can overwhelm prey in a choreographed feeding frenzy.
Scientists, however, think they travel together as a form of protection from predators, according to National Geographic. That's not to say that frenzies never occur. When threatened, the shoal will group together with other shoals to take down the predator. They inhabit both still and moving sections of the vast fresh-water Amazon River basin system. In the wild, a good portion of their diet consists of fins nipped from the tails of larger fish.
Additional items on a piranha's menu can include bits of flesh, whole small fish, insects, aquatic invertebrates and occasionally, plant material in the form of figs and other ripe fruit. At the Smithsonian's National Zoo, red-bellied piranhas receive a gelatin diet a mixture of greens, proteins and micronutrients in a gelatin base , smelt, shrimp, herring and earthworms. Red-bellied piranha reproduction begins with a courtship display involving swimming in circles. These piranhas are nest builders, with males creating bowl-shaped crevices in the sediment where eggs are placed.
The eggs are laid in clusters and are attached to submerged aquatic vegetation. It is theorized that spawning could potentially correlate to the Amazon's wet season.
Smaller piranha search for food during the day, while larger fish tend to be more active at dawn and dusk. Skip to main content. Entry passes are required for all guests, including infants.
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