Latin name

Pygocentrus nattereri

Other name

Red piranha

Identification

The red-bellied piranha has a short, deep body shape. Its cross-section is compressed.

All piranhas have large mouths with sharp, protruding teeth. Their flat, wedge-shaped teeth have sharp tips that dig into the tough skin of their prey. The teeth on both jaws have the same structure. The upper teeth are smaller and fit into the gaps between the lower teeth when the mouth is closed. Powerful muscles power the jaws. The lower jaw protrudes forward, and the teeth curve backwards. The teeth on the lower jaw are 1-2 mm long.

Features of fish fins

Dorsal spines (total): 0; Dorsal soft rays (total): 16 - 18; Anal spines: 0; Anal soft rays: 27 - 30.

Fish colouring

Piranha species differ from one another in their coloration. Most have olive-green or black backs with a bluish tinge and dark or silvery-gray bellies and sides.

Distribution

Piranhas inhabit waterways on the South American continent, including the Amazon, Paraguay, Paraná, and Essequibo river basins. The largest populations live in Colombia, Venezuela, Guyana, Paraguay, Brazil, and central Argentina.

Habitat

Tropical freshwater pelagic fish

pH range: 5.5–7.5

dH range: ?–20 Temperature: 23–27°C.

Size

These fish have a body length of about 15 cm, with a maximum length of 50 cm. Their maximum body weight is 3.9 kg.

Behavior

Red-bellied piranhas live in large schools and spend most of their time searching for prey. These typically riverine fish can be found in the ocean during high tide. However, they are unable to spawn in the ocean. They are quite voracious and can only live in rivers abundant with fish. They are most often found in shallow water, at great depths, and in muddy water.

Food and feeding habits

Piranhas rely on speed and surprise when hunting prey. Sometimes they lie in wait, attacking when the opportunity arises. The entire school rushes at the prey and devours it. Each fish acts independently of the others. Piranhas swiftly pounce on their prey as a school. Attacked fish panic and try to escape in all directions, but the fast piranhas catch them one by one. They swallow small fish whole and tear off pieces of flesh from large prey, immediately swallowing them so they can bite into their prey again. A school of adult piranhas can destroy everything in its path, including aquatic vegetation, which the males pull out. However, scientists have found that piranhas do not touch healthy catfish of the genus Hoplosternum. These catfish swim fearlessly up to the piranhas and eat the parasites from their skin.

Piranhas primarily feed on fish and birds in the water.

Reproduction

The fish spawn from March to August, laying several thousand eggs. The incubation period lasts 10–15 days depending on the water temperature. The eggs are laid on tree roots hanging over the water, where they are guarded. Breeding success can vary greatly from year to year, depending on how badly the savannah has flooded. The large eggs stick to plants and are not attacked by their parents.

Fishing

This species is not commercially important.

Relationship with a person

This is one of the most famous species of piranha. It is known as a dangerous freshwater predator that threatens animals and humans. However, there has never been a documented case of a piranha attack resulting in human death. This does not mean, however, that these fish never bite humans or other animals that enter the water. Such behavior is almost never caused by aggression on the part of the fish, but rather by self-defense or abnormal weather conditions, which cause piranhas to behave differently than usual. Piranhas pose no danger to humans unless they feel threatened.

The meat of these fish is considered a delicacy in South American countries such as Brazil and Peru.