THE INSATIABLE HUNGRY FISH
There are approximately 20 species of piranha found living in the Amazon River, with only four or five of them posing any danger. Most piranha species are quite harmless and docile, but the ones with the nasty reputation for aggressive behavior are the red-bellied piranha, Pygocentrus nattereri.
Size / Weight / Age
Max length : 41.5 cm SL male/unsexed; max. published weight: 3,000 g
Freshwater; benthopelagic; pH range: 5.8 - 7.0
Climate / Range
Tropical; 23°C - 27°C
South America: Amazon and Orinoco River basins, north and eastern Guiana Shield rivers, and northeastern Brazilian coastal rivers.
It occurs in rapids mostly, but is also captured in deep zones of main rivers with the use of fish bait. It is essentially a carnivore, feeds on small fish, crabs, mammals, lizards and coleopteran insects. Its opportunistic behavior allows it to adapt to various biotopes. It is timid and not aggressive but it possesses powerful teeth that can cause serious bites, and is therefore, potentially dangerous.
in the Rio Negro River
From the moment tiny baby piranhas hatch from their microscopic eggs, they come into the world armed and dangerous. Baby piranha will feast on tiny crustaceans, fruits, seeds, and aquatic plants. Once they reach about 1.5 inches in length they begin feeding on the fins and flesh of other fish that wander too closely. As they grow larger they begin to venture out in groups (shoals) of about 20 fish where they use a variety of hunting strategies to kill and eat their prey. Heck, they don't kill their prey first, they just start eating the victim alive - that's what makes them so ferocious. Adult piranha have been known to eat their own babies. Talk about brutal!
An Unstoppable Force of Nature
The unpredictable piranha, these will hit any lure you through in front of them. They will range between at a couple of pounds with some getting bigger. These are best seen on a green stick grill on the side of the river during a nice shore lunch after a long day of fishing with a nice cold beer by the side. A small piranha less than 3-inches will take the tip of your finger off if it gets a good chomp, I almost lost mine, now imagine one this size, it will take the whole finger off.
Razor Sharp Teeth
Piranhas are world-famous for their razor-sharp teeth. Native peoples of South America will catch the piranha and use their teeth to make tools and weapons. Even the fisherman who catch these vicious little predators have to be careful when the fish is out of water. A single piranha out of water is still dangerous enough to take off the flesh, or the odd toe, from an unwary fisherman.
Adult piranha will eat just about anything - other fish, sick and weakened cattle, even parts of people. Sickly cattle that have stooped their heads down to drink from the river have been grabbed by the mouth and nose and pulled into the water, completely devoured minutes later. As wicked as it all sounds, piranha have a useful function in the Amazonian jungles just like any other predators in the wild. They are part of the checks and balances Mother Nature employs to eliminate the weak and sick so only the strong survive.
Predator Becomes Prey
As ferocious and fearsome as the piranhas are, they are not invulnerable. As young the piranhas are a tasty part of many other creatures' diet. As voracious adults the piranha feed on young herons that fall from the trees while learning to fly, or young caimans (a type of small alligator) that are too little to defend themselves. When the floodplains of the Amazon run dry during the dry season the piranha are stranded in isolated lagoons, where they languish and die from lack of oxygen. The adult herons will then feed on the piranha that once ate their young. Caimans will feast on the piranhas that ate their young kin, as they lay dying in their shrinking pools. Such is the circle of life.