• Species: Serrasalmus manueli

  • Species: Serrasalmus marginatus

  • Species: Pygocentrus nattereri

  • Species: Serrasalmus rhombeus

  • Species: Pygocentrus nattereri

  • Species: Serrasulmus elongatus

  • Species: Serrasalmus marginatus


19 May 2017

Piranhas are a group of fish endemic to South America with a reputation for being vicious man-eaters, but in reality this is not true. Although they are more than capable of doing immense damage with their razor sharp teeth, they are actually highly timid and will not attack humans unless they are cornered as a last resort. It is thought that their reputation was earned when Teddy Roosevelt visited South America where locals isolated a population of piranhas to make them hungry before pushing a cow into the river to demonstrate their appetite for meat to the American president. Piranhas make fascinating specimens for the aquarium and come in a variety of sizes and forms.

Taxonomy and Distribution

Piranhas are characins belonging to the subfamily Serrassalminae, which also includes closely related fish such as pacu. The genera in this family considered to be true piranhas are Pristobrycon, Serrasalmus, Pygocentrus and Pygopristis. Piranhas inhabit the waters of the Amazon basin, the Orinoco river as well as the São Francisco and Paraguay-Paraná river systems.

General Care

Piranhas make highly rewarding aquarium fish, but all too often they are kept in less than adequate conditions. Many species are capable of reaching sizes in excess of 30cm and so it is imperative that they be provided with a large aquarium. An aquarium at least 200l in size is required for a shoal of sub adults, but an even larger aquarium is needed for fully-grown specimens. Piranhas are somewhat nervous fish and the tank should be furnished with plenty of bogwood and plants to provide shade and cover whilst the lighting should also be dimmed. Although piranhas have successfully been housed with other fish, it is generally best to keep them in a species only tank, as other fish may become targets of aggression or predation. They should be kept singly or in groups of four or more, if the species is gregarious. Groups should never be smaller than this as the specimens will show aggression towards one another, potentially killing each other.

Pygocentrus nattereri Red Bellied Piranha

The red bellied piranha is the most commonly seen species of piranha in the aquatic trade. At 30cm in length, it is widespread throughout much of South America. Adult specimens sport a grey body flecked with iridescent scales with a vivid orange-red ventral area whilst juveniles are silver in colour with dark spots on their body. Although thought to be omnivorous in the wild, it rarely accepts non-meaty foods in captivity. Instead, feed it on foods such as mussels, whitebait and prawns. Frozen chicks and small ‘pinky’ mice often sold as reptile food can also be offered.

Serrasalmus rhombeus Black Piranha

The black piranha is a species widespread throughout much of South America, although the exact range of this species is an issue for debate. Species have been officially collected from countries such as Venezuela, Suriname, French Guiana, Ecuador, Peru, Bolivia, Brazil and Guyana. However, it has also been suggested that its distribution is restricted to Guyana, with collections from other areas actually being different species. The largest form of this species is capable of reaching 45cm and as such is only suitable for the larger piranha aquarium. Although this species is sociable when young, adults will not tolerate any other fish and as such specimens should be kept individually. Powerful filtration and frequent water changes are necessary as this species is intolerant of poor water quality. Meaty foods such as whitebait, river shrimp and earthworms should be fed to this species.

Serrasalmus manueli Green Tiger Piranha

The green tiger piranha is thought to be the largest of the predatory piranhas, with the largest recorded specimen weighing in at 2.5kg and being over 40cm in length. The body is silver in colour with vertical pale green stripes along its flanks, which are boldest in juveniles. Provide this species with a large, extremely well filtered aquarium with a strong flow and good aeration. It is highly sensitive to metabolites and therefore should only ever be kept in a mature aquarium with large, regular water changes. It should be kept singly as it will not tolerate any other fish. Feed on seafood and other meaty foods.

Serrasalmus marginatus Marginatus Piranha

The marginatus piranha is endemic to the waters of Argentina, Brazil, Uruguay and Paraguay. At around 20cm in length it is one of the smaller piranha species, making it easier to maintain good water quality. Although somewhat nervous, it is well suited to captivity. Seafood is the ideal food for this species, although it will eat a variety of foods.

Serrasalmus geryi Gery’s Pirambeba

The Gery’s pirambeba is a small species (reaching around 18cm in the aquarium) endemic to the Rio Araguaia and Rio Tocantins drainages in Brazil. Provide a well-oxygenated aquarium with a sandy substrate with plenty of driftwood and dim lighting. Highly efficient filtration is required for this species in the form of a sump or external canister filter. Do not keep this species with any other species. There is some debate over whether or not this species can be housed with other conspecifics although it is recommended that this species is kept singly as an artificial closed system makes fish behaviour unpredictable. This fish will relish live or frozen foods such as bloodworm and whitebait as well as seafoods such as prawns and mussels.

Serrasulmus elongatus Pike Piranha

The pike piranha is widespread throughout the Orinoco and Amazon River basins. At 30cm long, it is a particularly active fish and must therefore be provided with a large aquarium. Furnish the tank with plenty of plants, roots and branches coupled with a dark substrate. This species is intolerant of poor water quality and should be provided with highly efficient filtration. It also appears to prefer a high flow rate. As with many piranhas, this species will not tolerate any other fish and as such specimens should be kept singly. A variety of seafood such as mussels, cockles and prawns are relished by this species as well live or frozen feeds such as bloodworm and Tubifex.