Fish, Tanks and Ponds


Fish, Tanks and Ponds
A comprehensive guide to fish

Pygocentrus nattereri

Red-bellied piranha

Red-bellied piranha, Pygocentrus nattereriRed-bellied piranha, Pygocentrus nattereri
Photos by Andy Rapson

Etymology:

Pygocentrus: Greek, pyge = rump + Greek, kentron = sting

General Notes:

As indicated by their wide distribution Pygocentrus nattereri are very tolerant of a wide range of conditions. They are often seen for sale when juvenile as pictured above, at this stage they are no more demanding than the majority of other tropical fish. But they do grow very rapidly and they can begin to turn on each other if improperly housed or too few specimens are kept. Although these fish live in shoals it is entirely possible to keep a single specimen if space is short.
Although these fish have a ferocious reputation in reality they are quite shy and timid in the aquarium unless feeding. They are relatively sedate, preferring to simply hover in one spot rather than dash around their aquarium.
Even so, when dealing with large specimens please take every precaution because they do have very strong jaws armed with teeth designed for cutting and they may panic if cornered.
Piranha don't need huge open spaces because they are relatively sedate but they do like to hover close to places to hide. As such their aquarium should be quite busy with lots of tank decor and in order to reduce their shyness fairly dim lighting should be used.

Feeding

Red-bellied piranha, Pygocentrus nattereri is exclusively carnivorous. small mammals, birds and fish are all taken. Red-bellied piranha hunt in large shoals and each member of the shoal is equipped with powerful jaws and large cutting teeth enabling them to easily over power prey which a single fish would not be able to do.
In captivity they will take dead prey such as whole fish, lancefish, whitebait and sardines are ideal for this. They will also take whole prawns, insects such as crickets and worms.
Red meat should be avoided because fish are unable to digest hard animal fat and red meat from domestic animals has a very high fat content. There is absolutely no need to use live prey (feeder fish) telling yourself that it is 'nature' because their is nothing natural about dropping a domestic fish in to a tank of piranhas with no opportunity for escape. There is also the unnecessary risk of introducing a disease from this practice. When all said and done, using live food for these fish is simply animal abuse and it has no place in fish keeping.

In the UK it is illegal to use any live vertebrate as food.

Compatibility

Pygocentrus nattereri, is only compatible with its own kind when kept in large numbers in a very large aquarium. If only three or four specimens are kept together then the likely outcome is that a single fish will be the only survivor. Most other fish will be eaten fairly quickly.

Sexing

The sexes are very similar in appearance. Adult females may appear more rounded and less brightly coloured than adult males. It is very difficult to sex these fish reliably.

Breeding

Unusually for Characins, Pygocentrus nattereri go through a courtship and defend a territory as a pair which they will go on to use for spawning. Post spawning the parents continue to protect their brood until the fry become independent and move away from their parents territory.

Breeding has occurred in captivity. A well conditioned pair should be added to a 100gall (450 litres) aquarium which has lots of decor (bogwood) and is very densely planted in places.
If spawning does occur the pair will lay thousands of adhesive eggs over the plants and continue to watch over them. Unlike cichlids they don't attack every fish which comes near and they may not even show any interest in other fish (unless hungry). It is thought that their mere presence as a top predator is enough to deter most egg snatchers.

Depending on the temp the fry will hatch after 36 - 48 hrs and become free swimming about a week later. The fry are easy to rear accepting newly hatched brine shrimps and finely powdered food. Due to the very high number of eggs, some quite severe culling will have to take place in order to raise some healthy fish rather than a tank of cannibalistic runts of varying size.

Wild status

Pygocentrus nattereri is widespread and very common. The species is under no threat in the wild.

Additional information

In nature Pygocentrus nattereri can reach 16 ins, (40cms) but specimens above 12 ins (30cms) are extremely rare in captivity.

Information at a glance

pH: 6 - 8
dGH: 4 - 20
Temperature: 22 - 28°C (72 - 82°F)
Lighting:
Diet: Carnivore
Size: 40cm (16in) usually less.
Min tank size: 450 litres
Difficulty level: Moderate
Aquarium type: Species.
Swimming level: Middle

Distribution and habitat

distribution map for Pygocentrus nattereri

Origin: Wide spread across South America.

Habitat: Rivers, swamps, lakes.

Classification

Kingdom: Animalia
Phylum: Chordata
Class: Actinopterygii
Order: Characiformes
Family: Serrasalmidae
Genus: Pygocentrus
Species: P.nattereri, (Kner 1860)

Other common names:
Red Piranha, Redbelly, Common Piranha.

Synonyms:
Pygocentrus stigmaterythraeus, Serrasalmus nattereri,
Serrasalmo piranha,
Pygocentrus piraya,
Serrasalmus ternetzi,
Pygocentrus ternetzi,
Serrasalmo ternetzi,
Pygocentrus altus,
Rooseveltiella nattereri.