1 00:00:01,840 --> 00:00:07,920 Speaker 1: Welcome to Brainstuff, a production of iHeartRadio, Hey Brainstuff. Lorn 2 00:00:07,960 --> 00:00:13,520 Speaker 1: voleban here. When Theodore Roosevelt went on a hunting expedition 3 00:00:13,600 --> 00:00:17,200 Speaker 1: in Brazil in nineteen thirteen, he got his money's worth. 4 00:00:18,239 --> 00:00:21,120 Speaker 1: Standing on the bank of the Amazon River, he watched 5 00:00:21,160 --> 00:00:25,680 Speaker 1: piranhas attack a cow with shocking ferocity. It was a 6 00:00:25,720 --> 00:00:28,639 Speaker 1: scene out of a horror film of water boiling with 7 00:00:28,720 --> 00:00:32,320 Speaker 1: frenzied piranhas and blood, and after about a minute or two, 8 00:00:32,720 --> 00:00:38,239 Speaker 1: a skeleton floating to the suddenly calm surface. Roosevelt was 9 00:00:38,320 --> 00:00:42,080 Speaker 1: appropriately shocked and talked about it in his nineteen fourteen 10 00:00:42,120 --> 00:00:46,720 Speaker 1: book Through the Brazilian Wilderness. He wrote, they are the 11 00:00:46,760 --> 00:00:49,720 Speaker 1: most ferocious fish in the world. They will snap a 12 00:00:49,720 --> 00:00:52,960 Speaker 1: finger off a hand incautiously trailed in the water. They 13 00:00:53,040 --> 00:00:56,040 Speaker 1: mutilate swimmers. In every river town in Paraguay there are 14 00:00:56,080 --> 00:00:58,640 Speaker 1: men who have been thus mutilated. They will rend and 15 00:00:58,680 --> 00:01:02,160 Speaker 1: devour alive any wounded man or beast, for blood in 16 00:01:02,200 --> 00:01:08,040 Speaker 1: the water excites them to madness. Thus the American legend 17 00:01:08,120 --> 00:01:12,200 Speaker 1: of the piranha had begun. Hollywood picked it up from 18 00:01:12,240 --> 00:01:16,080 Speaker 1: there with the nineteen seventy eight horror flick Piranha, directed 19 00:01:16,080 --> 00:01:20,120 Speaker 1: by cult film Officionado Jo Dante, notably right after the 20 00:01:20,120 --> 00:01:23,759 Speaker 1: smash hit Jaws came out in nineteen seventy five, When 21 00:01:23,840 --> 00:01:27,800 Speaker 1: flesh eating piranhas are accidentally released into a summer resorts rivers, 22 00:01:28,040 --> 00:01:32,800 Speaker 1: the guests become their next meal. It was followed by 23 00:01:32,920 --> 00:01:36,800 Speaker 1: nineteen eighty one's Piranha two The Spawning, which was James 24 00:01:36,800 --> 00:01:40,520 Speaker 1: Cameron's directorial debut, and then a comedic remake of the 25 00:01:40,560 --> 00:01:44,119 Speaker 1: original in twenty ten Pirana three D, followed by its 26 00:01:44,160 --> 00:01:49,520 Speaker 1: sequel in twenty twelve, Pirana three Double D. All of this, 27 00:01:49,880 --> 00:01:53,920 Speaker 1: although purposefully silly, cemented the idea of the piranha as 28 00:01:53,960 --> 00:01:59,080 Speaker 1: a threat in our minds. But is this fish's vicious 29 00:01:59,080 --> 00:02:05,520 Speaker 1: reputation desert let's find out. First off, we're not talking 30 00:02:05,560 --> 00:02:09,919 Speaker 1: about gargantuan monsters here. Piranhas top out at about two 31 00:02:09,960 --> 00:02:13,280 Speaker 1: feet long that's sixty centimeters, and most are only about 32 00:02:13,280 --> 00:02:16,960 Speaker 1: eight inches or twenty centimeters and weigh just a few pounds. 33 00:02:18,200 --> 00:02:21,200 Speaker 1: The most aggressive of the roughly twenty species found in 34 00:02:21,200 --> 00:02:24,200 Speaker 1: the Amazon River, the red bellied piranha, is on the 35 00:02:24,200 --> 00:02:26,919 Speaker 1: small end of the spectrum and usually weighs about three 36 00:02:27,000 --> 00:02:31,440 Speaker 1: pounds or a little less than one and a half kilos. However, 37 00:02:31,720 --> 00:02:35,120 Speaker 1: in the case of piranhas, it's not the size that counts. 38 00:02:35,440 --> 00:02:39,360 Speaker 1: It's the bite. A piranha's teeth they're only about a 39 00:02:39,440 --> 00:02:44,239 Speaker 1: quarter inch long around four millimeters, but they're very finely serrated, 40 00:02:44,639 --> 00:02:49,720 Speaker 1: and the whole jaw mechanism is designed for chomping efficiency. 41 00:02:49,919 --> 00:02:53,200 Speaker 1: The teeth are spaced in an interlocking pattern, so when 42 00:02:53,240 --> 00:02:56,639 Speaker 1: a piranha jaw snaps shut, the top teeth and bottom 43 00:02:56,680 --> 00:03:01,160 Speaker 1: teeth interlace like dozens of pairs of scissors, and their 44 00:03:01,240 --> 00:03:04,680 Speaker 1: jaws are strong they can bite right through the bone 45 00:03:04,840 --> 00:03:11,440 Speaker 1: of say a human tow. Furthermore, piranhas don't chew. When 46 00:03:11,480 --> 00:03:13,840 Speaker 1: they bite down, the chunk of flesh they take out 47 00:03:13,840 --> 00:03:17,040 Speaker 1: of their prey goes right into their bellies. They just 48 00:03:17,280 --> 00:03:21,359 Speaker 1: keep snapping their jaws shut and filling themselves up. Also, 49 00:03:21,639 --> 00:03:25,760 Speaker 1: paranas are very efficient team eaters. A school and a 50 00:03:25,760 --> 00:03:30,160 Speaker 1: feeding frenzy will rotate continuously, so as each piranha takes 51 00:03:30,160 --> 00:03:32,120 Speaker 1: a bite, it moves out of the way so that 52 00:03:32,160 --> 00:03:34,600 Speaker 1: the fish behind it can get a bite, and so on. 53 00:03:35,880 --> 00:03:38,280 Speaker 1: They take turns at such speed that you get that 54 00:03:38,440 --> 00:03:42,760 Speaker 1: boiling water effect. If a large enough school was aggressive 55 00:03:42,840 --> 00:03:46,680 Speaker 1: enough It's entirely possible for piranha's too strip an animal 56 00:03:46,680 --> 00:03:48,560 Speaker 1: as big as a cow in just a few minutes, 57 00:03:48,840 --> 00:03:54,080 Speaker 1: if not under sixty seconds. But the key thing to 58 00:03:54,160 --> 00:03:57,320 Speaker 1: know about Roosevelt and his story is that although he 59 00:03:57,760 --> 00:04:01,880 Speaker 1: explored the Brazilian Amazon as an avid hunter, he wasn't 60 00:04:02,000 --> 00:04:06,440 Speaker 1: exactly the average tourist. He was a former US president 61 00:04:06,520 --> 00:04:09,920 Speaker 1: traveling with dozens of journalists, and his guides wanted him 62 00:04:09,960 --> 00:04:14,280 Speaker 1: to be very pleased with his trip. Feeding frenzies are 63 00:04:14,320 --> 00:04:18,120 Speaker 1: not an everyday occurrence. Roosevelt's guides in Brazil had set 64 00:04:18,200 --> 00:04:21,840 Speaker 1: up the scene for their famous guest. They set nets 65 00:04:21,880 --> 00:04:24,159 Speaker 1: to close off a small part of the river and 66 00:04:24,240 --> 00:04:27,200 Speaker 1: tossed hundreds of piranhas into it, trapping them at a 67 00:04:27,279 --> 00:04:31,720 Speaker 1: larger density than their usual school of twenty plus. By 68 00:04:31,720 --> 00:04:34,200 Speaker 1: the time they threw that poor cow into the water, 69 00:04:34,680 --> 00:04:39,760 Speaker 1: the poor piranhas were stressed and starving, So eating an 70 00:04:39,920 --> 00:04:43,560 Speaker 1: entire cow in a minute or two is not the norm. 71 00:04:43,600 --> 00:04:49,000 Speaker 1: But what and how do piranhas usually eat. Attacking a live, 72 00:04:49,240 --> 00:04:52,320 Speaker 1: land based animal isn't out of the question for piranhas. 73 00:04:52,839 --> 00:04:55,560 Speaker 1: They have been known to attack sick or old animals 74 00:04:55,600 --> 00:04:58,440 Speaker 1: that come to drink from the river. When a cow 75 00:04:58,480 --> 00:05:01,480 Speaker 1: lowers its head, they'll clamp off to its face. If 76 00:05:01,480 --> 00:05:03,960 Speaker 1: the cow is too weak to fight back, the piranhas 77 00:05:03,960 --> 00:05:06,640 Speaker 1: will drag it into the water and beat it. But 78 00:05:06,800 --> 00:05:10,400 Speaker 1: live mammals are not the mainstay of their diet. Mostly 79 00:05:10,640 --> 00:05:14,920 Speaker 1: in that category they're scavengers. The skeletons of people and 80 00:05:15,040 --> 00:05:18,239 Speaker 1: other land based animals found in the Amazon apparently eaten 81 00:05:18,279 --> 00:05:22,240 Speaker 1: by piranhas weren't attacked alive. They were already dead when 82 00:05:22,240 --> 00:05:26,240 Speaker 1: the piranhas got to them. As with other fish, land 83 00:05:26,279 --> 00:05:28,880 Speaker 1: based mammals are by no means a big part of 84 00:05:28,920 --> 00:05:33,600 Speaker 1: the purana's diet. They eat other fish, mostly including sometimes 85 00:05:33,600 --> 00:05:38,160 Speaker 1: other puranas, along with insects, worms, and shrimp. They will 86 00:05:38,240 --> 00:05:42,080 Speaker 1: ambush prey by lurking and then dashing out, but puranas 87 00:05:42,200 --> 00:05:45,920 Speaker 1: aren't even strictly carnivores. They'll eat pretty much anything they 88 00:05:45,920 --> 00:05:49,760 Speaker 1: can get, including fruits and other plants, especially when they're young. 89 00:05:51,520 --> 00:05:55,120 Speaker 1: The truth is that, contrary to legend, most piranhas don't 90 00:05:55,160 --> 00:05:59,320 Speaker 1: really attack anything. Most of the species and the Amazon 91 00:05:59,440 --> 00:06:02,479 Speaker 1: survive in entirely by taking small bites out of the 92 00:06:02,480 --> 00:06:04,920 Speaker 1: fins and scales of other fish as they pass by. 93 00:06:05,839 --> 00:06:09,040 Speaker 1: The fish swim away only slightly disturbed, and their fins 94 00:06:09,040 --> 00:06:12,920 Speaker 1: and scales grow back. Humans can also get in necked 95 00:06:13,240 --> 00:06:16,760 Speaker 1: deep enough to need stitches, and sadly, that is happening 96 00:06:16,800 --> 00:06:20,000 Speaker 1: more often in recent years, as dams and human habitation 97 00:06:20,240 --> 00:06:23,240 Speaker 1: having encroached on piranha's native territory in the fresh water 98 00:06:23,320 --> 00:06:28,000 Speaker 1: ponds and creeks of South America. To come full circle 99 00:06:28,040 --> 00:06:32,080 Speaker 1: of life, piranhas themselves have few predators, aside from humans 100 00:06:32,279 --> 00:06:34,920 Speaker 1: who sometimes catch them as food or kill them as 101 00:06:34,920 --> 00:06:39,080 Speaker 1: a pest. Even though puranhas are small, they're seldom eaten 102 00:06:39,120 --> 00:06:42,320 Speaker 1: by larger fish that tend to gulp their prey that 103 00:06:42,480 --> 00:06:46,680 Speaker 1: razor sharp bite would really hurt going down. But during 104 00:06:46,680 --> 00:06:50,560 Speaker 1: the dry season, piranhas are eaten regularly by herons and 105 00:06:50,640 --> 00:06:53,839 Speaker 1: cayman lizards. When water levels are low and the fish 106 00:06:53,920 --> 00:06:57,480 Speaker 1: end up trapped in increasingly small ponds but no food, 107 00:06:58,000 --> 00:07:01,080 Speaker 1: Unable to defend themselves, the herons and cayman's come in 108 00:07:01,279 --> 00:07:05,360 Speaker 1: and finish them off. Because of that lack of predators, 109 00:07:05,520 --> 00:07:08,920 Speaker 1: many countries of outlawed the import or possession of piranhas, 110 00:07:09,040 --> 00:07:12,840 Speaker 1: even as aquarium pets, the risk they might be released 111 00:07:12,840 --> 00:07:15,520 Speaker 1: into local waters and cause a serious threat to the 112 00:07:15,560 --> 00:07:21,080 Speaker 1: ecological balance there is too great. But still as hazardous 113 00:07:21,080 --> 00:07:25,040 Speaker 1: as piranhas can be in large and hungry numbers, you 114 00:07:25,120 --> 00:07:27,320 Speaker 1: probably don't need to be as worried about them as 115 00:07:27,360 --> 00:07:35,760 Speaker 1: Theodore Roosevelt or the B movies tell you. Today's episode 116 00:07:35,840 --> 00:07:38,360 Speaker 1: is based on the article can piranhas really strip a 117 00:07:38,440 --> 00:07:40,520 Speaker 1: cow to the bone in under a minute? On how 118 00:07:40,560 --> 00:07:43,800 Speaker 1: stuffworks dot com, written by Julia Layton. Brain Stuff is 119 00:07:43,840 --> 00:07:46,320 Speaker 1: production by Heart Radio in partnership with how stuffworks dot 120 00:07:46,400 --> 00:07:49,600 Speaker 1: Com and is produced by Tyler Klang. Four more podcasts 121 00:07:49,680 --> 00:07:52,960 Speaker 1: my heart Radio, visit the iHeartRadio app, Apple Podcasts, or 122 00:07:53,000 --> 00:07:54,840 Speaker 1: wherever you listen to your favorite shows.