Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff. Lorn
Speaker 1: voleban here. When Theodore Roosevelt went on a hunting expedition
Speaker 1: in Brazil in nineteen thirteen, he got his money's worth.
Speaker 1: Standing on the bank of the Amazon River, he watched
Speaker 1: piranhas attack a cow with shocking ferocity. It was a
Speaker 1: scene out of a horror film of water boiling with
Speaker 1: frenzied piranhas and blood, and after about a minute or two,
Speaker 1: a skeleton floating to the suddenly calm surface. Roosevelt was
Speaker 1: appropriately shocked and talked about it in his nineteen fourteen
Speaker 1: book Through the Brazilian Wilderness. He wrote, they are the
Speaker 1: most ferocious fish in the world. They will snap a
Speaker 1: finger off a hand incautiously trailed in the water. They
Speaker 1: mutilate swimmers. In every river town in Paraguay there are
Speaker 1: men who have been thus mutilated. They will rend and
Speaker 1: devour alive any wounded man or beast, for blood in
Speaker 1: the water excites them to madness. Thus the American legend
Speaker 1: of the piranha had begun. Hollywood picked it up from
Speaker 1: there with the nineteen seventy eight horror flick Piranha, directed
Speaker 1: by cult film Officionado Jo Dante, notably right after the
Speaker 1: smash hit Jaws came out in nineteen seventy five, When
Speaker 1: flesh eating piranhas are accidentally released into a summer resorts rivers,
Speaker 1: the guests become their next meal. It was followed by
Speaker 1: nineteen eighty one's Piranha two The Spawning, which was James
Speaker 1: Cameron's directorial debut, and then a comedic remake of the
Speaker 1: original in twenty ten Pirana three D, followed by its
Speaker 1: sequel in twenty twelve, Pirana three Double D. All of this,
Speaker 1: although purposefully silly, cemented the idea of the piranha as
Speaker 1: a threat in our minds. But is this fish's vicious
Speaker 1: reputation desert let's find out. First off, we're not talking
Speaker 1: about gargantuan monsters here. Piranhas top out at about two
Speaker 1: feet long that's sixty centimeters, and most are only about
Speaker 1: eight inches or twenty centimeters and weigh just a few pounds.
Speaker 1: The most aggressive of the roughly twenty species found in
Speaker 1: the Amazon River, the red bellied piranha, is on the
Speaker 1: small end of the spectrum and usually weighs about three
Speaker 1: pounds or a little less than one and a half kilos. However,
Speaker 1: in the case of piranhas, it's not the size that counts.
Speaker 1: It's the bite. A piranha's teeth they're only about a
Speaker 1: quarter inch long around four millimeters, but they're very finely serrated,
Speaker 1: and the whole jaw mechanism is designed for chomping efficiency.
Speaker 1: The teeth are spaced in an interlocking pattern, so when
Speaker 1: a piranha jaw snaps shut, the top teeth and bottom
Speaker 1: teeth interlace like dozens of pairs of scissors, and their
Speaker 1: jaws are strong they can bite right through the bone
Speaker 1: of say a human tow. Furthermore, piranhas don't chew. When
Speaker 1: they bite down, the chunk of flesh they take out
Speaker 1: of their prey goes right into their bellies. They just
Speaker 1: keep snapping their jaws shut and filling themselves up. Also,
Speaker 1: paranas are very efficient team eaters. A school and a
Speaker 1: feeding frenzy will rotate continuously, so as each piranha takes
Speaker 1: a bite, it moves out of the way so that
Speaker 1: the fish behind it can get a bite, and so on.
Speaker 1: They take turns at such speed that you get that
Speaker 1: boiling water effect. If a large enough school was aggressive
Speaker 1: enough It's entirely possible for piranha's too strip an animal
Speaker 1: as big as a cow in just a few minutes,
Speaker 1: if not under sixty seconds. But the key thing to
Speaker 1: know about Roosevelt and his story is that although he
Speaker 1: explored the Brazilian Amazon as an avid hunter, he wasn't
Speaker 1: exactly the average tourist. He was a former US president
Speaker 1: traveling with dozens of journalists, and his guides wanted him
Speaker 1: to be very pleased with his trip. Feeding frenzies are
Speaker 1: not an everyday occurrence. Roosevelt's guides in Brazil had set
Speaker 1: up the scene for their famous guest. They set nets
Speaker 1: to close off a small part of the river and
Speaker 1: tossed hundreds of piranhas into it, trapping them at a
Speaker 1: larger density than their usual school of twenty plus. By
Speaker 1: the time they threw that poor cow into the water,
Speaker 1: the poor piranhas were stressed and starving, So eating an
Speaker 1: entire cow in a minute or two is not the norm.
Speaker 1: But what and how do piranhas usually eat. Attacking a live,
Speaker 1: land based animal isn't out of the question for piranhas.
Speaker 1: They have been known to attack sick or old animals
Speaker 1: that come to drink from the river. When a cow
Speaker 1: lowers its head, they'll clamp off to its face. If
Speaker 1: the cow is too weak to fight back, the piranhas
Speaker 1: will drag it into the water and beat it. But
Speaker 1: live mammals are not the mainstay of their diet. Mostly
Speaker 1: in that category they're scavengers. The skeletons of people and
Speaker 1: other land based animals found in the Amazon apparently eaten
Speaker 1: by piranhas weren't attacked alive. They were already dead when
Speaker 1: the piranhas got to them. As with other fish, land
Speaker 1: based mammals are by no means a big part of
Speaker 1: the purana's diet. They eat other fish, mostly including sometimes
Speaker 1: other puranas, along with insects, worms, and shrimp. They will
Speaker 1: ambush prey by lurking and then dashing out, but puranas
Speaker 1: aren't even strictly carnivores. They'll eat pretty much anything they
Speaker 1: can get, including fruits and other plants, especially when they're young.
Speaker 1: The truth is that, contrary to legend, most piranhas don't
Speaker 1: really attack anything. Most of the species and the Amazon
Speaker 1: survive in entirely by taking small bites out of the
Speaker 1: fins and scales of other fish as they pass by.
Speaker 1: The fish swim away only slightly disturbed, and their fins
Speaker 1: and scales grow back. Humans can also get in necked
Speaker 1: deep enough to need stitches, and sadly, that is happening
Speaker 1: more often in recent years, as dams and human habitation
Speaker 1: having encroached on piranha's native territory in the fresh water
Speaker 1: ponds and creeks of South America. To come full circle
Speaker 1: of life, piranhas themselves have few predators, aside from humans
Speaker 1: who sometimes catch them as food or kill them as
Speaker 1: a pest. Even though puranhas are small, they're seldom eaten
Speaker 1: by larger fish that tend to gulp their prey that
Speaker 1: razor sharp bite would really hurt going down. But during
Speaker 1: the dry season, piranhas are eaten regularly by herons and
Speaker 1: cayman lizards. When water levels are low and the fish
Speaker 1: end up trapped in increasingly small ponds but no food,
Speaker 1: Unable to defend themselves, the herons and cayman's come in
Speaker 1: and finish them off. Because of that lack of predators,
Speaker 1: many countries of outlawed the import or possession of piranhas,
Speaker 1: even as aquarium pets, the risk they might be released
Speaker 1: into local waters and cause a serious threat to the
Speaker 1: ecological balance there is too great. But still as hazardous
Speaker 1: as piranhas can be in large and hungry numbers, you
Speaker 1: probably don't need to be as worried about them as
Speaker 1: Theodore Roosevelt or the B movies tell you. Today's episode
Speaker 1: is based on the article can piranhas really strip a
Speaker 1: cow to the bone in under a minute? On how
Speaker 1: stuffworks dot com, written by Julia Layton. Brain Stuff is
Speaker 1: production by Heart Radio in partnership with how stuffworks dot
Speaker 1: Com and is produced by Tyler Klang. Four more podcasts
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