Piranhas are a unique creature that has won its so popularity, not only because of its appearance, but also due to the many myths they are told in. Unfortunately only a few species having been breed, some of the species that have commonly bred include Serrasalmus nattereri, S. spilopleura, S. gibbus, S. rhombeus. Another species that is considered relatively easy to breed is S. maculatus.
Whichever you choose, you should have an aquarium that is at least 100 gallons. A group of 5-6 piranhas is quite appropriate, however if you want them breeding, the best is to keep them in pairs so that there are no other fishes to bother them. To find ae mating pair, you can pick two adult Piranhas, one is thick and the other is thinner. In most cases, thick piranhas represent females and thinner Piranhas represent males. Just make sure you are not looking at them after they have been fed. Though having found males and females doesn