Tometes camunani is endemic to the rapids and fast-flowing sections of the Trombetas River in Pará state, Brazil. It is a rheophilic species adapted to high-current, oxygen-rich environments and feeds primarily on epilithic algae scraped from rocks — an unusual feeding strategy among serrasalmid fish. It grows to impressive sizes exceeding 50 cm and is a powerful, muscular fish with a deep, compressed body and strong pectoral fins suited to battling currents.
In the aquarium, Tometes camunani requires an exceptionally large tank — ideally 2000 litres or more — with very strong directional flow produced by powerful circulation pumps. The substrate should consist of smooth river pebbles and coarse sand, and the tank should feature large, smooth river boulders. This species requires the highest levels of water oxygenation and quality of any pacu species available in the hobby.
Due to its restricted range and specialist requirements, Tometes camunani is very rarely available and commands considerable prices when it does appear. It is a fish for serious specialists only. Stable, clean, heavily oxygenated water is essential to its survival, and any lapse in water quality or oxygenation can be fatal. It is peaceful with large, comparably-sized fish in sufficiently spacious conditions.
