|Common name||Black Piranha, White Piranha
|Scientific name||Serrasalmus rhombeus|
|Synonyms||Serrasalmus niger (invalid)|
|Origin||Amazon basin and Guyana.|
|Tank setup||A large tank with bogwood, possibly a few robust or plastic plants for decor.
An adult will require a tank of 100 gallons plus. Heavy-duty filtration is essential. Dim lighting.|
|Compatibility||A highly predatory and aggressive carnivore, keep alone.|
|Water chemistry||Fairly soft, acidic water (pH 5.8-6.8) prefered, but not essential.|
|Feeding||Carnivore: Live or dead meaty foods. There is no particular need to feed live fish, as they can usually be weaned onto
thawed mussel, prawn, whitebait, etc. Earthworms may be useful with reluctant feeders. The use of "feeder fish" carries a strong risk of introducing disease.|
|Sexing||The anal fin of the male is extended at the front, on females it is straight.|
|Breeding||Eggs are laid among plants or in a pit in the substrate and defended by the parents.
Hatching takes around 2-3 days.|
|Comments||The piranha are infamous as highly dangerous carnivores. This reputation is somewhat exaggerated, but it
is wise to take precautions when carrying out tank maintenance, as they can inflict nasty bites. The fish may
actually appear rather timid if kept in a brightly lit aquarium with little cover.|
There has been a lot of confusion about this species in the past. This results partly from the change in colouration as the fish matures (see photos).
Young specimens are lighter in colour, and often referred to as the white piranha. Based on adult specimens, the fish was described as a
different species and assigned the name S. niger. However, this name is not considered valid due to the pre-existance of the name S. rhombeus.
However, the exact relationship of the white and black piranhas, i.e. the existence of different species, subspecies, or regional variants of the same species,
has probably not been definitively established.