A massive, fast-growing predatory catfish from the Amazon basin. Famous for its voracious appetite, bulldozer-like behavior, and distinct red caudal fin. Due to its enormous adult size (often exceeding 4 feet), it is strictly a 'monster fish' that requires a heated indoor pond or a colossal custom aquarium. It is highly predatory and will swallow absolutely any tank mate that can fit into its cavernous mouth.
At a Glance
Tank Requirements
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Water Parameters
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Temperament & Compatibility
Available Varieties
Each variety inherits the species defaults above. Only differences are highlighted.
Standard (Adult)
The fully grown adult Red-Tail Catfish. Requires heavy-duty filtration, bare-bottom or sand substrate, and a tank or pond measured in thousands of liters.
Same care requirements as the base species
Also known as: Adult, Monster, Full Grown
Juvenile (Grow-out)
Juveniles are commonly sold at 5-10cm. They grow at an astonishing rate (often up to an inch per month initially) and possess an incredibly fast metabolism. They must only be purchased if a pond or custom tank upgrade is already planned.
Differs in 5 traits from base species
Also known as: Baby, Juvenile, RTC Baby
Red-Tail Catfish Care Guide Summary
The Red-Tail Catfish, scientifically known as Phractocephalus hemioliopterus, belongs to the Catfish family group. Adults reach a maximum size of approximately 120 cm and have a depressed body shape with a fast growth rate. Classified as aggressive, this species primarily occupies the bottom zone of the aquarium and produces a extreme level of biological waste.
To thrive, the Red-Tail Catfish requires a freshwater only aquarium with a minimum volume of 3800 litres and a tank length of at least 300 cm. Water temperature should be maintained between 20°C and 28°C, with a pH range of 6–7.5 and a general hardness of 3–15 dGH. A moderate water flow is preferred. An aquarium test kit can help you monitor these values.
Due to its specialist needs, the Red-Tail Catfish is best suited for fishkeepers who can provide a carefully planned setup. This species is available in 2 varieties: Standard (Adult) and Juvenile (Grow-out). Each may differ slightly in size, temperament, or care needs, so it is worth checking the specific requirements of the variety you plan to keep.
Red-Tail Catfish Habitat Setup
When setting up an aquarium for the Red-Tail Catfish, a moderate water flow best suits their natural preferences. Because this species occupies the bottom zone, the aquarium layout should prioritise sufficient floor space with hiding spots among rocks, wood, or dense planting. Useful additions include a sand substrate to accommodate their sifting behaviour, smooth gravel or rounded substrate to protect their sensitive barbels, and driftwood, which can serve as both a hiding place and a dietary supplement. Keepers should note that expect substrate disturbance, so lightweight décor should be secured and live planted layouts may be difficult to maintain, as this species tends to uproot or consume vegetation. Browse aquarium sand substrate options to find the best fit.
Red-Tail Catfish Compatibility Notes
Classified as aggressive, the Red-Tail Catfish is adaptable and can be kept singly or in a small group, offering flexibility when planning a community tank. When choosing tankmates, any fish small enough to fit in its mouth will likely be eaten. Selecting tankmates that favour different water layers from the bottom zone can help reduce competition and territorial overlap.
Red-Tail Catfish Feeding & Diet Considerations
The Red-Tail Catfish is a predatory species that will readily consume small fish, so nano or bite-sized tankmates should be avoided and is primarily active at dusk and dawn, so offering food shortly after lights-off ensures it receives adequate nutrition. Find quality Red-Tail Catfish fish food for this species.
Frequently Asked Questions About Red-Tail Catfish
How big does Red-Tail Catfish get?
Red-Tail Catfish (Phractocephalus hemioliopterus) typically reaches a maximum adult size of approximately 120 cm. They have a depressed body shape and a fast growth rate.
What tank size does Red-Tail Catfish need?
A minimum aquarium volume of 3800 litres and a tank length of at least 300 cm are recommended for Red-Tail Catfish. This ensures enough swimming space and helps maintain stable water conditions.
What water parameters does Red-Tail Catfish need?
Red-Tail Catfish thrives in freshwater only conditions with a temperature range of 20–28°C, a pH between 6 and 7.5, and a general hardness of 3–15 dGH. A moderate water flow is preferred.
Is Red-Tail Catfish peaceful or aggressive?
Red-Tail Catfish is classified as aggressive with an aggression score of 7 out of 10. Careful tankmate selection is essential to avoid conflict.
Can Red-Tail Catfish live alone?
Yes, Red-Tail Catfish can be kept singly or in a group. They are flexible and adapt well to both setups.
Does Red-Tail Catfish have any special tank requirements?
Yes. Red-Tail Catfish benefits from sand (sifters), smooth gravel (sensitive barbels), and driftwood (digestion/hiding) in the aquarium. These features help replicate their natural habitat and promote overall health and well-being.
Similar Species
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Panda Corydoras
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Red-Bellied Piranha
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Black Pacu
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The Black Pacu (Tambaqui) is a massive, incredibly fast-growing Amazonian fish. Closely related to Piranhas, they possess crushing, human-like teeth evolved for cracking nuts and seeds. Due to their enormous adult size (often exceeding 3 feet and 60 lbs) and extreme bioload, they are completely unsuitable for standard home aquariums and require colossal custom tanks or heated indoor ponds.
Pictus Catfish
Pimelodus pictus
An extremely active, striking silver catfish with black spots and incredibly long barbels, native to South America. While peaceful toward similarly sized tank mates, they are highly effective nocturnal predators that will easily swallow small fish (like Neon Tetras) whole. They are scaleless and possess sharp pectoral spines that can easily become entangled in aquarium nets.