White Piranha Care Guide
Serrasalmus rhombeus, the redeye piranha, is a solitary predator from the Amazon and Orinoco basins with one of the strongest bites among fish.
Compiled by Aquairi from published sources · Published · Updated
Overview
Serrasalmus rhombeus, the redeye or black piranha, is the type species of its genus. It is a solitary predator widely distributed across northern South America. Coloration varies with water type, with paler fish in turbid waters and darker fish in clear or blackwater environments.
Taxonomy
- Family: Serrasalmidae
- Genus: Serrasalmus
- Scientific name: Serrasalmus rhombeus
- Order: Characiformes
Habitat
The species occurs in the Amazon and Orinoco drainages, the Essequibo and other Guiana Shield rivers, and coastal rivers of northeastern Brazil. Adults favour larger, deeper river channels and the vicinity of rapids, while juveniles use stiller, densely vegetated areas.
Tank requirements
- Minimum tank volume: 500 L
- Temperature: 22-28 °C (72-82 °F)
- pH: 5.5-7.5
- GH: 4-18 °dGH
- Lifespan: 10-20 years
Diet
Serrasalmus rhombeus is an opportunistic carnivore. It eats fish, insects, fallen fruit and plant matter, and also takes scales and fins from other fish and feeds on carcasses in the river. FishBase places it at a trophic level around 4.0. In captivity it is fed meaty foods two times daily.
Compatibility
This is not a sociable species and normally lives solitarily as an adult. It is highly aggressive and should be housed alone; all other fish are at risk and should be avoided as tankmates.
Conservation status
IUCN Red List: Least Concern. The species remains widespread despite commercial fishing and aquarium-trade pressure.
White Piranha (Serrasalmus rhombeus) Breeding Guide
Overview
Serrasalmus rhombeus is a serrasalmid found across the Amazon and Orinoco river systems, the Essequibo River and the coastal rivers of the Guiana Shield. According to FishBase and Wikipedia it reaches a large size, with maximum reported standard length around 41.5 cm and occasionally larger. Wikipedia notes the species is not sociable and normally lives solitarily, which is the central obstacle to any breeding attempt.
Sexing
No reliable external sexual dimorphism is documented for Serrasalmus rhombeus in the consulted sources. Within the genus, sexes are difficult to separate visually and females in spawning condition are generally plumper than males, but no confirmed field-tested method is described for this species.
Breeding Setup
Because adults are solitary and highly aggressive, housing a compatible pair together long enough to spawn is the principal challenge; the consulted sources do not describe a successful home setup. Wikipedia notes that, at least when breeding in the wild, the fish defend an area around the nest placed among thick vegetation, which indicates that dense planting and ample space would be prerequisites.
Spawning Behavior & Trigger
Wikipedia reports that breeding fish defend a nest site set among thick vegetation. Beyond this, no spawning sequence, trigger, or egg count is documented for Serrasalmus rhombeus in the consulted sources, and no confirmed captive breeding is recorded.
Common Challenges
The decisive challenges are the solitary, aggressive temperament of adults and the very large tank required, which together make controlled pairing impractical for almost all hobbyists. Without documented spawning data, attempts carry high risk of injury between fish and no reliable protocol to follow.