Red Belly Pacu Aquarium Care, Feeding and Native Habitat Information
The Red Belly Pacu is one of the largest freshwater species that can be kept in a home aquarium. Originating in the Amazon Basin of South America, this huge cousin of the Piranha grows quickly and can weigh over 50 pounds. As juveniles the Red Belly Pacu almost perfectly mimics a Red Belly Piranha for defense, but once they are large enough, not many fish species will ever bother them. Although they have special requirements (a massive aquarium with strong filtration), if those requirements are met they are easy to care for and are a very hardy and long lived (20+ years) species that is readily available from both local and online retailers.
Red Belly Pacus require and aquarium of 500 gallons (preferably much larger) as they will grow large and will do it quickly; they also need to be able to turn around and are much happier in groups (and anything less than 500 gallons would unlikely support more than one specimen). They prefer a sand to fine gravel substrate with several large pieces of driftwood and rock structures for shelter as well as soft, acidic, blackwater conditions. Live plants are usually out of the question because the Red Belly Pacus will generally devour them as the main part of their diet; although it has been said that they tend to stay away from Java Moss... perhaps floating Anacharis could be a tasty treat now and then. Strong and efficient filtration is a necessity to ensure good health and clean water due to the extremely large biological load this species will have on their environment; high-end (possibly custom), external biological and mechanical filtration (e.g., a sump-style wet/dry filter) will be needed and quality chemical filtration is also recommended. Red Belly Pacus are generally a gentle, peaceful species, but they can become territorial once they are older and much larger. They can be mixed with large cichlids, South American catfish, and various large Pleco species; some compatible tank mates could be Oscars, Arowana, Lima Shovelnose Catfish, Redtail Catfish, Tiger Shovelnose Catfish, L-234 Plecos, Polka Dot Lyre Tail Plecos, Sailfin Plecos, Geophagus altifrons, and Parrot Cichlids. Ultimately, tank mates will need to be chosen wisely and should at least be over 10"-12" as adults.
Red Belly Pacus are omnivorous and will pretty much eat anything, but in their natural environment they mainly eat surface and aquatic insects as well as large amounts of vegetable matter. The main part of their diet focuses on vegetable matter as well as some small fruits (aquatic plants, broccoli, romaine lettuce, strawberries, etc.), but they will also eat meaty food items such as crickets, earthworms, bloodworms, and brine shrimp; they should also be fed quality pellet foods for both carnivores and herbivores alike. A variety of the foods mentioned will keep them happy and healthy.