Giant raphael catfish (Megalodoras uranoscopus) care guide

Group
Freshwater fish
Other names
Giant talking catfish, Giant thorny catfish, Megalodoras irwini (old trade name)
Family
Doradidae (thorny catfishes)
Origin
South America: the Amazon, Tocantins and Essequibo basins (Brazil, Peru, Guyana and nearby countries).
Water
freshwater
Maximum size
53 cm
Temperature
21–24°C
pH
5.8–7.4
Hardness
Soft to hard, up to 25 dGH
Minimum tank
2000 litres
Care level
intermediate
Temperament
peaceful

Care

The giant raphael catfish is a large, heavily armoured talking catfish with a row of large bony plates (scutes) along each side and an attractive pattern that it keeps into adulthood. PlanetCatfish gives a maximum of 53 cm standard length, while FishBase records females up to 60 cm. It is not commonly imported. It is peaceful but bulky. We have estimated a minimum of about 2,000 litres for an adult, as no source gives a figure; a tank at least 2.5 m long would be needed. Provide large pieces of bogwood and wide pipes or caves to hide in, guard the heater, and use strong external filtration. It is mainly active at night in aquariums, although FishBase notes wild fish are active by day. PlanetCatfish gives 21–24 °C, pH 5.8–7.4 and hardness up to 25 dGH. FishBase gives 22–25 °C. Keep nitrate low with large regular water changes, as a fish this size produces a lot of waste. Handle with great care: the scutes and fin spines are sharp and easily catch in nets, so move it in a container rather than a net where you can. Like other doradids it can make croaking sounds. Sexing is unknown. It is listed as Least Concern on the IUCN Red List (assessed 2020) and is fished commercially for food in parts of its range. Selling: our policies require the adult size and long-term tank needs to be stated clearly in the listing. Large fish must travel by a specialist live-animal courier (see the Livestock shipping guide). Sources: PlanetCatfish (planetcatfish.com/common/species.php?speciesid=143); FishBase (fishbase.se/summary/Megalodoras-uranoscopus.html). Checked October 2026.

Diet

An omnivore. In the wild it eats fruits that fall into the water and freshwater snails. In aquariums it takes sinking catfish pellets and tablets, earthworms, prawns, frozen bloodworm and snails. Feed in the evening, and include plant matter such as fruit or vegetables now and then.

Breeding

Not reported in home aquariums (PlanetCatfish). FishBase notes that wild fish mature at about 54 cm, a size few aquarium specimens reach.

Compatibility and tank mates

Peaceful towards other fish, but adults will eat very small fish and snails. Keep with other large peaceful fish such as large doradids, pimelodids too small to eat it, large characins and calm large cichlids. Not suitable for a planted community tank of small fish.

Last updated 5 October 2026. Community-edited care guide on Aquatic-Auctions.

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