The Piranha Thread


Aug 19, 2003
Black Piranha, Megapiranha Have Most Powerful Bites of Fish Living or Extinct, Researcher Finds ... 160727.htm

New research finds that the black piranha (shown above) and the extinct giant piranha, or megapiranha, have the most powerful bites of carnivorous fishes, living or extinct, once body size is taken into account. (Credit: Courtesy of Guillermo Orti)

Dec. 20, 2012 — The black piranha and the extinct giant piranha, or megapiranha, have the most powerful bites of carnivorous fishes, living or extinct, once body size is taken into account, find researchers in a paper recently published in Scientific Reports. The research paper, "Mega-Bites: Extreme jaw forces of living and extinct piranhas," highlights the piranhas' specialized jaw morphology, which allows them to attack and bite chunks out of much larger prey.

Guillermo Ortí, the George Washington University Louis Weintraub Professor of Biology in the Columbian College of Arts and Sciences, is one of the authors of the paper. His research focuses on the evolution of fishes in general, but specializes on Amazonian fishes, to unravel evolutionary relationships based on DNA sequence data. In 2010, Dr. Orti along with other researchers participated in an expedition to the Xingu and Iriri rivers in Amazonia to collect the data on the fish.

Piranhas' aggressive nature, relatively small size and accessible populations make them a suitable group of predatory vertebrates in which to study the evolution of extreme biting capabilities. Even at their small body sizes, diet studies indicate that piranhas will attack and bite chunks of bony fins and flesh from prey many times larger than themselves.

In spite of their reputation, no quantitative data or empirical estimates regarding the piranhas biting abilities were available.

The paper reports the first bite-force measurements taken from wild specimens of the largest species of carnivorous piranha in the Amazon, the black piranha, and describes the underlying functional morphology of the jaws that allows this creature to bite with a force more than 30 times greater than its weight. The powerful bite is achieved primarily due to the large muscle mass of the black piranha's jaw and the efficient transmission of its large contractile forces through a highly modified jaw-closing lever.

The expedition was organized and filmed by National Geographic. A subsequent program called Megapiranha aired on the National Geographic Channel featured the expedition and focused on the creature that existed millions of years ago.

"It was very exciting to participate in this project, travel one more time to the Amazon to be able to directly measure bite forces in the wild," said Dr. Orti. "I learned a lot of biomechanics from my colleagues while collecting valuable specimens for my own research."

The authors also reconstructed the bite force of the megapiranha, showing that for its relatively diminutive body size, the bite of this fossil piranha dwarfed that of other extinct mega-predators, including the whale-eating shark and the Devonian placoderm. Research at the Ortí lab at GW continues to focus on reconstructing the genealogical tree of fishes including piranhas based on genomic data.

Scientific Reports is a primary research publication from the publishers of Nature, covering all areas of the natural sciences.

Story Source:

The above story is reprinted from materials provided by George Washington University.

Journal Reference:

Justin R. Grubich, Steve Huskey, Stephanie Crofts, Guillermo Orti, Jorge Porto. Mega-Bites: Extreme jaw forces of living and extinct piranhas (Serrasalmidae). Scientific Reports, 2012; DOI: 10.1038/srep01009

Edit to amend title.
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Carnivorous fish attack bathers in Argentina

Man treated in Rosario, 25 Dec

The bathers were cooling off in a heat wave

A school of carnivorous fish related to the piranha has attacked bathers in an Argentine river, injuring about 70.

Thousands of bathers were cooling off in the Parana River in Rosario, 300km (186 miles) north of Buenos Aires, on Christmas Day when the attack happened.

Officials blamed the attack on the palometa fish, describing the event as "exceptional".

Paramedics said dozens of people had their extremities attacked and some had lost digits.

Director of lifeguards in Rosario, Federico Cornier, said bathers suddenly began to complain of bite marks on hands and feet as they cooled off in a heat wave.

He said the palometa was "a type of piranha, big, voracious and with sharp teeth that can really bite".

Mr Cornier said: "This is not normal. It's normal for there to be an isolated bite or injury, but the magnitude in this case was great... this is an exceptional event."

Paramedic Alberto Manino told Associated Press some children he had treated had lost entire digits.
Hmmm. The name of the river should have been warning enough.
Carnivorous fish attacks injure 10 people in Argentinian river ... nian-river
• Piranha-like 'palometas' bite bathers in Paraná river
• Similar attack in December left 70 people injured

Associated Press in Buenos Aires, Saturday 18 January 2014 16.57 GMT

Palometa victim

A man is treated after he being bitten by a palometa, a type of piranha, in a similar attack in the Paraná river in December. Photograph: Silvina Salinas/AP

Attacks by a school of carnivorous fish have injured at least 10 people bathing in an Argentinian river since Thursday.

The latest attack by the "palometas" was confirmed on Saturday. The fish have been described by the local director of lifeguards as "a type of piranha, big, voracious and with sharp teeth that can really bite".

Media reports said the injured included a boy who suffered a foot wound while floating in the river.

The attacks took place in the Paraná River in Rosario, 186 miles north-east of Buenos Aires. Seventy people who were cooling off from high temperatures were injured there in late December by the same piranha-like fish. They included seven children who lost parts of their fingers or toes.

Experts say unusually high temperatures during the austral summer and lower numbers of species such as caiman that preyed on the fish could be causing the attacks.
This is a little old, but it's notable because this was at Lake of the Ozarks in Missouri, U.S.

Fisherman bitten by piranha
Friday, August 24, 2012

A Murkywater man injured in a crash last weekend was bitten by a flesh-eating piranha he caught fishing near the Dead Veterans Memorial Bridge yesterday.

Brady Plummer, 61, was fishing for bluegill with his friend, Avery Bliss, when he caught the piranha around 6:30 p.m. “I said, ‘Avery, look at this thing.’ And Avery said, ‘Dang it, Brady, that’s a piranha.’”

Plummer, who has two broken arms, a broken leg, and stitches on his forehead, said he was bitten on the finger when he attempted to remove the hook from the fish’s mouth. “I said, ‘Avery, look at these teeth,’ and that’s when it got me. Dang it if he didn’t bite me on the one place that wasn’t covered by the cast.”

Three stitches were required to close the inch-long gash in Plummer’s right index finger.

The fish measured 10 inches long and weighed 1 lb. 4 oz.

Plummer said he was using a piece of raw chicken for bait. “I know that sounds weird, but you never know what you’re going to catch in Danger River, and I figure everything likes chicken.”

Piranha are native to South America. They first gained notoriety in 1914, after President Theodore Roosevelt wrote about seeing a school of piranha devour a cow while he was exploring Brazil the year before.

Plummer’s catch was not the first time a piranha has been caught in the United States. Last year, two piranhas were caught in Lake of the Ozarks in Missouri. This past summer, another piranha was caught in Tellico Lake in Tennessee. The two bodies of water are not connected.

Scientists believe the fish were “pets” that were later released into the lakes, and not part of a school of piranha. Piranha need warm water and cannot survive if the temperature drops below 50 degrees. Prior to Plummer being bitten, there had been no reported piranha attacks in the United States.

Bliss confirmed the fish was indeed a red-breasted piranha after comparing in to a picture in the book, “Fish Species of the World.” Afterward, the two men debated what they should do with the exotic fish. “Avery said, ‘Brady, that fish tried to eat you. If I was you, I’d eat it.’ So, that’s what I did.”

Plummer said after Bliss filleted the fish, Plummer took it home to his wife, Marge, who rolled the two tiny fillets in cornmeal and deep fried them. “We ate it for supper,” he said. “It was okay. It tasted kind of like crappie, but bonier.”

Asked if he had a photograph of the piranha, Plummer said they tried to take a picture with Bliss’ cell phone. “He couldn’t figure out how to do it,” Plummer said. “The first time, he accidently dialed my house. The second time he tried, he called his son in Florida.”

Aaaargghh! Hopefully she was dead before the piranhas started feeding.

A six-year-old girl has been found dead in Brazil after being surrounded and devoured by a large shoal of piranhas.

Family members said she was with her grandmother and four other children in a canoe, which capsized in a storm. Her grandmother managed to bring the other children back into the boat, but was not able to reach the victim, named by local media outlets as Adrila Muniz.

A group of townspeople in the northern state of Para helped to search for the girl, but found her unresponsive. The incident happened in the Maicuru River near the town of Monte Alegre on the afternoon of 27 January.

Family members told some local media that the girl may have drowned shortly after falling into the river, and could have been dead prior to being set upon by the piranhas. ...
How was she both 'devoured' and 'found'?
The report says the flesh from her legs was devoured, the rest of her found.
I see.
Nice image.
Apparently a pair of Piranhas have floated up in a Doncaster fishing lake!

From the Guardian yesterday evening:


(One of the suspected fish discovered in a Yorkshire lake. Photograph: SWNS)

"Late on Monday night, a reporter at the Doncaster Free Press received an unusual phone call. A piranha, one of the world’s fiercest predators normally found stalking the waters of the Amazon basin, had apparently been discovered in a lake in Doncaster..."

If they were found in that location as reported then maybe they were released as unwanted pet fish and soon died, perhaps?
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If they were found in that location as reported then maybe they were released as unwanted pet fish and soon died, perhaps?
As I understand it the cold winter water would 'do for them'.

I find this kind of thing annoying - it's a kind of potential environmental vandalism. Waters are not infinite resources, they support a weight of fish per acreage and if you introduce a foreign species and it thrives it's de facto at the expense of indigenous species. In this case the fish were never going to breed or survive, but other species from 'fish tanks' have caused big problems, like the top-mouth gudgeon at least two lakes have had to be drained and poisoned to eradicate them.

Even the humble goldfish will interbreed with crucians, a native cyprinid, causing "extinction by hybridisation" in enclosed environments. It's vandalism really.

Four bathers killed and over 20 injured in spate of deadly piranha attacks

Four bathers have been killed and over 20 people injured in a spate of ferocious piranha attacks causing alarm in Paraguay.


A 22-year-old man died after he was badly bitten by the predators as he swam in the Paraguay river, south of the capital Asuncion, at Itá Enramada on January 2.

His family saw him disappear from view and contacted the police leading to a search that lasted 45 minutes before his badly bitten body was found.

It is unusual for piranhas to be so aggressive and yet there have been numerous attacks in the region.

A 49-year-old man was also killed in the Paraguay river, in the town of Puerto Rosario, with his body found with bite wounds after he was reported missing.

There have also been many other reports of swimmers being bitten with more than seven reported on just New Year’s Day on the beach at the Bella Vista swimming club in Itapua.

maximus otter
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Please don't feed the piranhas.

A school of piranhas attacked holiday makers playing in a stream in a Brazilian resort on May 1, leaving at least eight people injured.

The fish tore at the bathers' legs and feet with their razor-sharp teeth, driving them out of the water and onto a tourist beach in Tarumã-Açu, a region northeast of Manaus, the capital city of the state of Amazonas.

Experts think the biting frenzy was a case of "mistaken identity" and that the piranhas were actually after the food that visitors at local restaurants sometimes throw into the river.