Red-Bellied Piranha Tank Requirements

Deep in the heart of the Amazon River swims a fish with some real jaws. The red-bellied piranha, true to its name, travels among 20-some varieties of piranhas that inhabit the Amazon and its lakes. Known as Pygocentrus nattereri, from the Serrasalmus family, and being the aggressive fish that they are, piranhas cannot be placed in a community tank as they will attack other species. However, a few other piranhas can be added to their own tank since they are usually found in groups in the wild.

  1. Special Tank Conditions

    • A tank containing piranhas should be of good size, at least 20 gallons, because red-bellied adults can grow as large as 1 foot in length and weigh up to 7 pounds. The Amazon River environment consists of soft, slightly acidic water with a temperature of about 79 degrees F., so a heater will be necessary to maintain the correct range of 75 to 84 degrees F. Good filtration is also a must when keeping piranhas.

    Feeding Habits and Preferences

    • Primarily carnivorous, red-bellied adults feed at dawn or late in the day and at night, while the young eat during the day. Other fish, worms, larvae, insects, crustaceans and algae are also preferred fare. While some believe they should feed live fish or meat, this is not necessary and piranhas will remain healthy without it. Bogwood, also called mangrove root, is a good plant for the tank and helps keep the pH, which should be between 5.5 and 7, consistent.

    Breeding in Captivity Possible But Difficult

    • Piranhas are egg-laying fish, but breeding in a tank is not easy. Filtering the water through plain peat with no additives may help create better conditions for breeding. The male will usually dig out an area for the eggs and guard the nest. If eggs are laid, they will hatch within a few days and once the babies are swimming freely they can be fed brine shrimp. There may be anywhere from 700 to several thousand eggs, and after hatching the female will also guard them.

    Not Quite "Jaws" But Be Careful

    • While movies and TV have somewhat exaggerated their ferociousness, piranhas can be dangerous. Use caution and avoid putting your fingers in the tank. Many people enjoy having and watching piranhas, finding them fascinating. A clean tank that is large enough will ensure your piranhas stay healthy.