The piranha, the soft version of the fear of the shark

The piranha, the soft version of the fear of the shark

Piranha, the “devil fish

The term “piranha” comes from the Tupi-guarani Amerindian languages spoken along the great rivers of South America (Amazon, the Argentinean Rio Parana, the Venezuelan Orinoco). It means “devil fish”: a long-standing reputation for voracity.

Pygocentrus and Serrasalmus

Of the vast family of tropical freshwater fishes that are the Characidae (as well as the grouse), the piranha itself designates 35 different species belonging to the genera Pygocentrus (4 species, including the red-bellied piranha), Serrasalmus (including the black-bellied piranha), or Mylesinus.

A recent freshwater fish
About 5 million years ago, the Atlantic Ocean flooded the Amazonian plain up to an altitude of 100 meters, saltwater fish then replacing freshwater ones: only the species living above this altitude survived, colonizing in turn the environment when the ocean, two million years later, withdrew.

How do piranha eat?
They are essentially frugivorous and phytophagous.

Most piranha species are frugivores (fruit eaters) or phytophagous (plant eaters): their teeth are round and not pointed. They are also the biggest, weighing up to six kilos.

The Kumara

This is the case of the Kumaru of the Maroni River in Guyana, a species fished to be eaten on the grill. The kumaru is still fished according to the ancestral method of the “nivrée”: a poisonous liana that is the “hali ali” is reduced in bundles immersed in water. It releases rotenone, a milky substance toxic for fish (also insects), but not for humans.

Piranhas, whose lungs are impregnated with it, are recovered downstream, weakened or dead from suffocation. Food advantage of the kumaru over local carnivorous species: it is not loaded with heavy metals, which is rarely the case in Guyana.

Digestive particularity… the intestine of the kumaru contains small worms, which help it to digest. They are not parasites, no concern for humans either.

Piranha, the carnivorous species
These are the ones that make our imagination run wild, because of their sharp triangular teeth, in a jaw reputed to be three times more powerful, in proportion, than that of an alligator!

A fisherman holding a piranha and lowering his lower lip with his finger, we discover its sharp and pointed teeth
The sharp teeth, cause of its reputation

Black or red-eyed piranha

The black piranha (Serrasalmus Rhombeus) has an eye that changes from white to red in the adult stage, hence its other name. Its scientific name comes from its diamond shape (in Latin, “rhombeus”) and the keel-like growth under its belly or “serras”.

This fish measures on average three kilos, for 40 to 50 cm length. Carnivorous, it feeds mainly on fish, frogs, insects and small mammals, the juveniles feeding by biting the scales and tail of larger fish.

Where are piranhas found?

This fish is present in Venezuela, Guyana and Surinam, in the northern tributaries of the Amazon. In French Guiana, it is found in the Maroni River, the Mana, the Oyapock, the Iracoubo and the Counamama. It is absent from the other rivers of Latin America.

Although shy and not very aggressive, the black piranha is known to have a bad temper : in aquarium, it tends to devour its fellow creatures…

Red-bellied piranha, the one of our fantasies

The red-bellied piranha (pygocentrus nattereri), owes its name to the red spot on the bottom of its flank. It is the emblem of our fantasies, with the most powerful jaws of the animal kingdom. Moreover, it lives in schools.

Piranha: danger in dry season

In fact, this fish is not a large predator: it is opportunistic. In the dry season, when it is locked in a pond, it cannibalizes itself for its survival: it then attacks everything that passes by, hence its danger to humans (especially fishermen) or livestock. On the other hand, in rivers, accidents are rare and never fatal.

It should be noted that in the environment, the piranha plays a purifying role by feeding on sick or dead fish.

Panic in Europe?

The Piranha does not tolerate water below 10°. But with global warming? Panic in 2014, when a fisherman pulled a piranha from a river in the Vosges and another got caught in nets in Belgian Flanders. Help, the invasion?

Since then, this fish has not swarmed, the specimens found having probably been released by owners anxious to get rid of them, without scruples for the environment.

Piranha in aquarium, a pet?
In fact, you have every right to have a piranha in your home. It is not without constraint: this big eater (fish, mussels, etc.) is also a big water polluter. It requires all the more stewardship, as it makes you a large aquarium, where cohabitation with other fish is at the expense of the latter.

NAC: piranhas in an aquarium

A new pet?

Piranha, its reputation as a man-eater!
The movie Piranhas by Joe Dante (1978) is to this fish what Jaws was to sharks: a couple of hikers break into a seemingly abandoned former army estate. They find a swimming pool, where the young woman convinces her companion to take a bath. They are both devoured by piranhas.

Tintin and the broken ear

It’s more reasonable with The Broken Ear, the sixth album of Tintin, who investigates the theft of an Arumbaya fetish. This one leads him to the fictional South American republic of San Theodoros, where he falls out of a boat into a river infested with piranhas. Hergé knew better, he will come out of it safe and sound.