Redtail Catfish
Phractocephalus hemioliopterus
Pimelodidae
No photo of this species yet
Got one of your own? Send it and your name goes under it.
About
The redtail catfish is the emperor of the Amazon and one of the most misplaced animals in the aquarium trade. Lithuanian shops sell it as a hand-sized juvenile with a comic red tail and a white belly stripe, and the price tag says nothing about what it becomes: FishBase records the adult at 135 cm total length and 44.2 kg, and a Lithuanian retailer's own listing for this fish states 134 cm and a minimum tank of 360 x 240 x 120 cm. Growth is fast and does not stop when the glass does — a well-fed juvenile outgrows every aquarium sold in a shop long before it is adult. It swallows whatever fits, tankmates and loose decor alike, and it lives around twenty years.
Care
Not an aquarium fish in any honest sense. Seriously Fish puts the minimum long-term home for one adult at 360 x 240 x 120 cm — 10,368 litres — which is a heated indoor pond, not a tank. Keep a single specimen: adults are territorial towards conspecifics and other large pimelodids. Sand substrate, nothing loose small enough to be swallowed, very heavy filtration and high dissolved oxygen, and a lid a startled 40 kg fish cannot shift. Feed adults sparingly, about once a week. Before buying, understand that no zoo or public aquarium is obliged to take yours when it stops fitting.
Diet
Opportunistic carnivore: fish, crabs and fallen fruit in the wild. Offer prawn, mussel, lancefish, earthworm and white fish fillet. No mammalian meat, no feeder fish, and far less food than it will happily accept.
Tankmate compatibility
Possible with care (19)
Avoid (399)
Computed by the AquaSage engine for a spacious reference tank — always check the full verdict for your exact setup in the calculator.
Telling males from females
What works for this species, most reliable first.
- Adult sizeA hint only · only across animals of the same age
In many cichlids, catfish and loaches one sex simply grows larger — usually the male, though there are well-known reversals.
Also in these lists
Similar species
Same category and the closest water parameters — if this species isn't quite it, start here.
Sold in Lithuania
These Lithuanian shops listed this species in their public catalogue (checked August 8, 2026). Stock moves — ask before you travel.
These links are unpaid: we get nothing for them and ask for nothing.
Frequently asked questions
- What tank size does a Redtail Catfish need?
- A Redtail Catfish needs an aquarium of at least 10000 litres (2641.7 US gallons) with a footprint at least 360 cm (141.7 in) long — for this species, swimming length matters as much as raw volume.
- What water parameters does a Redtail Catfish need?
- Redtail Catfish does best at 20–26 °C (68–78.8 °F), pH 5.5–7.5 and a general hardness of 2–12 °dGH.
- Is the Redtail Catfish suitable for beginners?
- Redtail Catfish is a demanding species best attempted with some experience — it needs stable, closely watched conditions to thrive.