So occasionally when resources are low and competition for food is high, piranhas have been known to take a chunk out of a fellow piranha, living or dead. Despite their flesh-eating reputation, some piranhas are omnivorous, eating more seeds than meat, and some even subsist on plants alone. Piranhas' closest relative, the pacu or tambaqui fish Colossoma macropomum , also lives on a mostly meat-free diet.
From anecdotes and observational research, scientists have known for a while that red-bellied piranhas make bark-like noises when caught by fishermen. Upon further examination, a team of Belgian scientists found that they make three distinctive types of vocalization in different situations.
The fish makes these two sounds using its swimbladder , a gas-containing organ that keeps fish afloat. Piranhas contract and relax muscles around the swimbladder to make noises of different frequencies. The third vocalization? Should the opposing fish not back down, the piranha will gnash its teeth together and chase its rival.
Red-bellied piranhas are particularly known as pack hunters. Though it might seem an advantageous hunting technique—more fish could theoretically take down a larger foe—the behavior actually stems from fear. So traveling in shoals has the effect of protecting the inner fish from attack. Further, shoals tend to have a hierarchy of larger, older fish towards the center and younger fish on the outer edges, suggesting that safety might be the true motivation.
In , researchers looked at shoal formation in captive red-bellied piranhas and found that the fish both breathed easier in larger shoals and responded more calmly to simulated predator attacks. The researchers also observed wild piranhas forming larger shoals in shallow waters where they might be more vulnerable. Like grizzly bears, wolves, sharks, and pretty much any large scary thing with teeth, piranhas will leave you alone if you leave them alone. Black piranhas and red-bellied piranhas are considered the most dangerous and aggressive toward humans.
Nonetheless, South American swimmers typically emerge from piranha-infested waters without loss of flesh. For swimmers, the danger comes when the water level is low, prey is scarce, or you disturb its spawn buried in the riverbed—basically situations where the fish either feel really threatened or really hungry, and thus become more aggressive.
For fishermen, untangling a piranha from a net or a hook is where things get dicey. In most cases , if they bite you, they only bite you once—and they usually go for the toes or feet. A study linked noise, splashing, and spilling food, fish, or blood into the river with three instances of piranha attacks on humans in Suriname.
Piranhas might be naturally attuned to pick up on the sound of fruits and nuts falling from trees and hitting the water and, thus, mistake splashing children for the noise associated with food. As for blood, it likely does not render a piranha senseless as the movies would suggest, but piranhas can smell a drop of blood in liters of water. So, if you are a bleeding, rambunctious child, a dip in the Amazon might not be the best idea.
Piranha soup is popular in the Pantanal region of Brazil, but many choose to serve the fish grilled on a banana leaf with tomatoes and limes for garnish.
I would estimate that they are able of quick bursts of 25mph or so, although if we're talking about sustained speed, it would be a lot less. Sep 25, 2, 92 51 chino hills, california. Fast enough that if it wants to, and your hand is in the tank, it will take a chunk out of you I've been bitten so fast it didn't even hurt I trded them to a guy with a g and a school of RBPs and he said he has had them shoot three feet into the air and land out of the tank to flop on the floor Piranha are cool.
Jan 8, 1, 1 36 Toronto, Ontario, Canada. Jan 19, 91 0 0 montana. Aug 22, 2 18 48 New Ringgold, Pa. BaileyIV;; said:. The Amazon, as a whole is an amazing river. The dry season of the Amazon river, from June to November the flow of the Amazon is at its weakest.
The width is between 3 and 9km. In the wet season however, December through to April, the rains come and the water flows more harshly. The width of the river enlarges to up to 30 miles wide in some parts. When it is flowing, the Amazon can reach an average speed of 4 mph.
With a good speed like that the Piranha needs to be able to swim against the current. This is why it needs a powerful body capable of maintaining its position in cover with a powerful river flow. Additionally it might need to strike at prey in the current, or scavenge floating food sources before they disappear.
With an ever present heron threat, they also need to keep out of the way of diving bursts. The Piranhas ability to put on prompt bursts of speed, for attacking prey and evading predators is the reason it has been surviving in the Amazon for close to 2 million years. The Piranha, for the environment is quite a fast fish. It can maintain itself against the river flow and has the speed to strike prey quickly.
As fast as the Piranha is, it is not faster than its predators.
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