What the sources say
Red-Bellied PiranhaPygocentrus nattereri
Every figure, record and mechanism on the Red-Bellied Piranha profile was written from a source, and this is the working table behind it: 42 claims checked word for word against these sources. The left column is what the page says. The right column is the source's own words, copied, not paraphrased; a ... marks a cut and[brackets] an insertion. Open any source and check it yourself.
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Source
01
Brejão 2024
Brejão (2024). Pygocentrus nattereri. The IUCN Red List of Threatened Species 2024: e.T186604A1815617.
- The page saysLeast Concern
- The source says
IUCN Red List category: Least Concern (LC).
Note: stats.conservationStatus; GBIF copy of the assessment
Source
02
Smithsonian's National Zoo and Conservation Biology Institute
Red-bellied piranha. Smithsonian's National Zoo and Conservation Biology Institute.
- The page saysRazor-sharp interlocking teeth, a red belly, and a school that doubles as cover from predators.
- The source says
triangular, razor sharp teeth, which interlock neatly with a matching set above
Note: tagline; red belly and cover-seeking school claimed below - The page saysa red belly
- The source says
Red-bellied piranhas are red on their undersides from chin and cheeks to belly.
- The page saysFins nipped from larger fish, bits of flesh, small fish, insects, aquatic invertebrates and occasional fruit
- The source says
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.
Note: stats.diet; "occasional fruit" keeps the source's "occasionally" - The page saysTriangular, razor-sharp interlocking teeth that bite down with great force and shearing ability
- The source says
triangular, razor sharp teeth, which interlock neatly with a matching set above. This design allows piranhas to bite down with incredible force and shearing ability.
Note: stats.superpower - The page saysThe fish can grow to a little over a foot long (30.5 centimeters) and weigh up to 4 pounds (1.81 kilograms)
- The source says
They can grow to be a little over a foot long (30.5 centimeters) and weigh up to 4 pounds (1.81 kilograms).
- The page saysThe Smithsonian's National Zoo gives a lifespan of 10 years or more
- The source says
Red-bellied piranhas have a lifespan of 10 years or more.
- The page saysUnder its high forehead sit powerful muscles attached to a short, stout lower jaw
- The source says
Beneath the high forehead are powerful muscles that attach to a short, stout lower jaw
- The page saysThe teeth are triangular and razor sharp, and they interlock with a matching set above
- The source says
fitted with triangular, razor sharp teeth, which interlock neatly with a matching set above.
- The page saysThe zoo says this design allows a piranha to bite down with incredible force and shearing ability
- The source says
This design allows piranhas to bite down with incredible force and shearing ability.
- The page saysThe teeth are not usually visible: thick, fleshy lips cover them
- The source says
these formidable teeth are not usually visible, being covered by thick, fleshy lips.
- The page saysIn the wild, a good portion of the diet is fins nipped from the tails of larger fish
- The source says
In the wild, a good portion of their diet consists of fins nipped from the tails of larger fish.
- The page saysThe menu can also include bits of flesh, whole small fish, insects, aquatic invertebrates (animals without backbones) and, occasionally, figs and other ripe fruit
- The source says
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.
- The page saysThe zoo calls these fish important scavengers
- The source says
these fish are important scavengers.
- The page saysSmaller piranhas search for food during the day. Larger fish tend to be more active at dawn and dusk.
- The source says
Smaller piranha search for food during the day, while larger fish tend to be more active at dawn and dusk.
- The page saysRed-bellied piranhas tend to travel in schools of 20 or more
- The source says
They tend to travel in schools of 20 or more individuals.
- The page saysA piranha's triangular teeth interlock with a matching set above, a design that gives its bite shearing ability.
- The source says
triangular, razor sharp teeth, which interlock neatly with a matching set above. This design allows piranhas to bite down with incredible force and shearing ability.
Note: vibe.reason
Source
03
Animal Diversity Web, University of Michigan
Pygocentrus nattereri (redbelly piranha). Animal Diversity Web, University of Michigan.
- The page saysAmazon and Paraná-Paraguay river basins, plus rivers of northeast Brazil and the Guianas
- The source says
can be found east of the Andes in the Parana-Paraguay and Amazon basin. They can also be found in rivers of northeast Brazil and the Guianas.
Note: stats.habitat - The page saysIt is native to South America east of the Andes: the Amazon and Paraná-Paraguay basins, plus rivers of northeast Brazil and the Guianas
- The source says
can be found east of the Andes in the Parana-Paraguay and Amazon basin. They can also be found in rivers of northeast Brazil and the Guianas.
- The page saysit can be seen lurking or ambushing prey in the daytime, and lists chasing and scavenging as two other ways it gets food
- The source says
In the daytime P. nattereri can be seen lurking or ambushing prey. Two other methods for obtaining food employed by P. nattereri are chasing and scavenging.
- The page saysone of the more dangerous and aggressive species of piranha, and listed injuring humans among its negative effects
- The source says
Pygocentrus nattereri is considered one of the more dangerous and aggressive species of piranha. Negative Impacts injures humans
- The page saysone of the most commonly used piranhas in the aquarium trade
- The source says
Pygocentrus nattereri is one of the most commonly used piranhas in the aquarium trade.
- The page saysthe species has been introduced to fresh waters in the United States many times, with reports from Florida, Hawaii, Massachusetts, Michigan, Minnesota, Ohio, Oklahoma, Pennsylvania, Texas and Virginia
- The source says
has been introduced to the freshwaters of the United States on numerous occasions. Introductions have been reported in Florida, Hawaii, Massachusetts, Michigan, Minnesota, Ohio, Oklahoma, Pennsylvania, Texas, and Virginia.
- The page saysThe fish were probably released from aquariums, and the account says that when one turns up in a lake, many state agencies use the chemical rotenone to kill the fish
- The source says
The fishes were probably releases from aquariums. When a piranha is found in a lake, many state agencies use the chemical rotenone to kill the fishes.
- The page saysin a 2002 account
- The source says
To cite this page: Putz, B. 2002. "Pygocentrus nattereri" (On-line), Animal Diversity Web.
Note: faq 1; account last updated 2002-10-17 - The page saysA 2002 Animal Diversity Web account
- The source says
To cite this page: Putz, B. 2002. "Pygocentrus nattereri" (On-line), Animal Diversity Web.
Note: faq 3
Source
04
Queiroz & Magurran 2005
Queiroz & Magurran (2005). Safety in numbers? Shoaling behaviour of the Amazonian red-bellied piranha. Biology Letters.
- The page saysa school that doubles as cover from predators
- The source says
shoaling has a cover-seeking function in this species
- The page sayshave a fearsome reputation
- The source says
Red-bellied piranha (Pygocentrus nattereri) shoals have a fearsome reputation.
- The page saysThe Amazon's flooded forests hold a variety and abundance of piranha predators. One team suggested predator defence may be an important reason for shoaling
- The source says
the variety and abundance of piranha predators in the flooded forests of the Amazon in which they live indicate that an important reason for shoal formation may be predator defence
- The page saysfish in small shoals perceive more risk, measured by how fast their gill covers beat
- The source says
individual perception of risk, as revealed by elevated ventilatory frequency (opercular rate), is greater in small shoals
- The page saysAfter a model cormorant (a fish-eating bird) simulated an attack, piranhas in shoals of eight settled back to resting rates faster than those in shoals of two
- The source says
exposure to a simulated predator attack by a model cormorant demonstrated that resting opercular rates are regained more quickly by piranhas in shoals of eight than they are in shoals of two
Note: "after" and "faster" paraphrase "exposure to" and "more quickly" - The page saysThe researchers concluded that shoaling has a cover-seeking function in this species
- The source says
these results show that shoaling has a cover-seeking function in this species
- The page saysExperiments with wild-caught piranhas supported the idea
- The source says
Experiments using wild-caught piranhas supported the hypothesis
Source
05
Millot, Vandewalle & Parmentier 2011
Millot, Vandewalle & Parmentier (2011). Sound production in red-bellied piranhas (Pygocentrus nattereri, Kner): an acoustical, behavioural and morphofunctional study. Journal of Experimental Biology.
- The page saysthree sounds to three behaviours
- The source says
three sounds were each associated to a specific behaviour
- The page saysa many-pulse sound during frontal display
- The source says
The first sound (type 1) was produced during frontal display; it had numerous pulses
- The page saysa single pulse during circling and fighting
- The source says
The second sound (type 2) was produced during circling and fighting behaviour; it was a single pulse
- The page saysa chasing sound linked to the jaw mechanism
- The source says
The third sound (type 3) corresponded to chasing behaviour and comprised three to four pulses, each lasting 3±1 ms, with a fundamental frequency of 1739±18 Hz. Using a laser vibrometer to study the swimbladder displacement when stimulated at different frequencies, it was demonstrated that the first two sounds corresponded to the swimbladder mechanism. By contrast, the third sound was associated with the jaw mechanism.
Source
06
Queiroz, Sobanski & Magurran 2010
Queiroz, Sobanski & Magurran (2010). Reproductive strategies of Red-bellied Piranha (Pygocentrus nattereri Kner, 1858) in the white waters of the Mamirauá flooded forest, central Brazilian Amazon. Environmental Biology of Fishes.
- The page saysboth males and females reached sexual maturity at around 160 mm
- The source says
Sexual maturation (of both males and females) occurred at around 160 mm.
- The page saysThe researchers also found two reproductive seasons a year, rather than one, tied to the flooding of the river
- The source says
piranhas had not one, but rather two annual reproductive seasons, tuned to water level fluctuation and the flooding pulse
- The page saysAt that point the sexually active fish became dark and lost most of their red colour
- The source says
At this point sexually active individuals (of both sexes) became dark and lost most of their red coloration.
- The page saysIn a two-year study in Brazil's Mamirauá Reserve that included over 3,000 fish
- The source says
We tracked the reproductive activity of piranhas in the flooded forests of Mamirauá Reserve, Central Brazilian Amazon, for 2 years, in an investigation that included over 3,000 individual fish.
Source
07
Vicentin, Costa & Súarez 2012
Vicentin, Costa & Súarez (2012). Population ecology of Red-bellied Piranha Pygocentrus nattereri Kner, 1858 (Characidae: Serrasalminae) in the Negro River, Pantanal, Brazil. Environmental Biology of Fishes.
- The page saysA study in the Negro River, in Brazil's Pantanal, estimated a life expectancy of 6.9 years for the piranhas there
- The source says
In the Pantanal, P. nattereri has a life expectancy (6.9 years) compatible with the 7 cohorts indicated by the growth curve.
How the table was made: a writer drafted the profile from these sources and logged each claim with its quote, a reviewer with nothing but this table checked every sentence said no more than its quote, and a script confirmed each quote appears word for word in the source. The method is in the site'sAbout page.