Red-bellied Piranha

Origin and False Myths:

It is widespread in most South American river basins. The myth of coordinated hunting in fierce packs is not scientifically supported; they gather in dense schools only as an anti-predator defense strategy (against caimans or otters) and tend to frantically "assault" in a group (feeding frenzy) only carcasses of animals already dead or dying in restricted pools during the dry season.

Morphology:

Massive bulldog head. The lower jaw protrudes sharply, and the teeth of the lower jaw are shaped like a triangular blade, perfectly interlocking with the upper row to instantly shear circular bites of meat. The scales are small, giving the fish a leathery, smooth appearance.

Tank Setup (Species-Only Tank):

Forget the movies: Piranhas kept alone or in pairs will spend their lives terrified behind a plant. They are schooling animals. The ethical minimum number is 6 specimens, but for this you will need a tank of at least 150-180 cm (60-72 inches, 150+ gallons). The tank should be set up in an amber biotope style (blackwater): dense tangles of mangrove branches and dim lighting or a massive presence of floaters. Without shade and continuous visual refuges, they will panic and violently crash against the glass. Use fine sand as a substrate.

Feeding (Avoid live goldfish!):

The use of live goldfish or guppies as food ("feeder fish") is cruel, nutritionally poor, and transmits lethal parasites to the aquarium. In nature, they are mainly opportunistic scavengers. Accustom juveniles right away to eating thawed cod steaks, mussels, whole shell-on prawns (excellent for the carotene of the red belly), cuttlefish, and earthworms. Strictly avoid beef heart or bovine meat: fish cannot digest mammal fats, which will deposit on their organs causing premature death.

Precautions and Filtration:

Filtration must be gigantic (industrial sumps) and water changes massive (up to 50% weekly) to dispose of the protein load of putrefying fish chunks. Golden safety rule: NEVER put bare hands in the tank if the fish are hungry or scared, and always use long metal tongs for maintenance or feeding.