The Red-tailed Catfish Phractocephalus hemioliopterus is easily recognized and one of the most attractive of the catfish species. As a member of the Pimelodidae family it is long whiskered, but Its beautiful red tail and white belly are its unmistakable characteristics. This fish is the only member of its genus and with its distinct appearance, it's only confused with an occasional hybrid that may appear from time to time. It is also known as the South American Red Tailed Catfish, Banana Catfish and Redtail Catfish. Flat-nosed Catfish and Antenna Catfish are generic names applied to this fish as well as some other members of its family.
This catfish gets really big. They can reach 3 feet or more in captivity and there are reports of specimens reaching up to 5 feet in the wild. Because of their large size they are a favorite game fish and anglers love them. The International Game Fish Association (IGFA) reports that the current world record weight for this fish is a whopping 123 lbs. 7 oz. (56 kg). This world record is held by Gilberto Fernandes for a specimen he caught in the Amazon River on April 3, 2010.
Even though the Red-tailed catfish is one of the larger fish in the Amazon, this is not a food fish for the natives. It has a dark colored flesh and according to Dr. Herbert R. Axelrod, in his book 'Aquarium Fishes of the World (1998)', the natives will only eat white flesh. According to Wikipedia, in an attempt to develop a viable food fish they have been hybridized with other fish species, like the Pseudoplatystoma sp. of Tiger Shovelnose. The resultant hybrids are generally known as Tiger Redtail Catfish. These will sometimes show up in the aquarium hobby under various common names.
Despite their attractive appearance, these catfish get very large and so are not recommended for the average aquarist. They are only able to be kept in a smaller aquarium as juveniles. Being fast growers they will quickly need a larger and larger aquarium. A minimum sized tank would be at least 1000 gallons, and for the largest sized ones it could easily be 1500 gallons or more. This is a huge tank, making them not really suitable for most homes. They are best left to public aquariums or only kept by advanced aquarists with the space and means to provide them with the appropriate habitat and care for their entire lifespan.
Red-tailed Catfish are not real active and would prefer a large cave or den to hang out in. If the tank is dimly lit, then just a few large pieces of bogwood will suffice. These fish are actually quite peaceful, but they have a big mouth and a hearty appetite. They can't be kept with smaller fish as these tank-mates will become lunch sooner or later. They are also territorial with their own kind as well as other catfish from the Pimelodidae family, but are fine kept with other same-sized large fish with a similar temperament.