Pacu Giants of the Tropical Fish Aquarium

Pacu are relatively new in the tropical fish market. Their quick growth and large size create difficulties for unknowing owners.

Pacu can be a wonderful addition to your tropical fish aquarium. Unfortunately, many aquarium owners are learning the hard way that Pacu are not always a good choice.

A Pacu is a tropical, freshwater fish from South American. They are relatives of the Piranha and to the untrained eye they are easily mistaken for Piranha. Like Piranha, Pacu have a mouth full of very dangerous looking teeth. Unlike Piranha, Pacu are herbivores and generally non-aggressive fish.

Unfortunately, many freshwater aquarium hobbyists who bring home a Pacu or two are not properly informed about their purchase. Pacu are relative newcomers to the U.S. tropical fish pet store market with the most common being the Red Belly Pacu. Often the information pet store employees are given regarding Pacu is incorrect and misleading. Consumers are led to believe they are purchasing an attractive tropical fish well suited to the average home aquarium.

The reality is that the cute quarter-sized Pacu in the pet store tank will quickly outgrow its aquarium. A Pacu will outgrow a 75 gallon aquarium within six months. Owners should expect to need a minimum of a 450 gallon aquarium to provide an adequate environment for their Pacu. Uneducated owners are first surprised and pleased as their Pacu grow. The pleasure turns to panic as owners must continue to purchase larger and larger aquariums to house their pets.

Pacu may live for up to twenty years and reach lengths of over three feet. Because of their size they can be destructive creatures. It is not unheard of for Pacu to have been electrocuted from biting the wiring of aquarium heaters. Pacu have also eaten chunks of in-tank floating thermometers. They dislodge aquarium decorations and damage filters. As Pacu grow they will even bump the glass lid off their aquarium during their excitement at feeding time.

Aquarium size is not the only issue that faces Pacu owners. Fish as large as Pacu require a substantial quantity of food. Small Pacu are content with tropical fish flakes. Wardley and Tetra both produce good quality flakes for aquarium fish. As Pacu grow, fish pellets, such as those for Cichlids are a suitable addition to their diet. Larger Pacu need greater quantities of food. As herbivores their nutritional needs are best met with a variety of fresh vegetables, fresh fruits and nuts. Their powerful jaws and sharp teeth allow them to eat almost anything. The entertainment of watching a Pacu eat a carrot stick cannot be ignored. It is not a good idea to attempt hand-feeding of a Pacu. While they are not as aggressive as their Piranha relatives, a Pacu bite is painful and will rip off flesh.

Pacu do exhibit wonderful personality traits. It is fun and relaxing to watch their aquarium antics. While Pacu do sometimes feed on smaller fish in their aquarium, they generally will live peacefully with other tropical fish of all sizes.

Pacu owners are faced with the difficult decision of what to do when they can no longer provide adequate housing for their pet. Pet stores do not generally accept these large fish back. Fear of disease and lack of space prevent many public aquariums from accepting a Pacu. Finding a new home for a Pacu can be very difficult. Apparently one owner even dumped a Pacu into a lake in Wisconsin when unable to properly care for it. A fisherman caught the Pacu. The Pacu would likely have not survived the winter. It is both cruel and illegal to release non-native fish but it is very likely that the owner of this Pacu was unable to find it another home and simply released it rather than killing it.

Pacu make great pets but should not be purchased without proper education.