TankBud

Redtail catfish

Phractocephalus hemioliopterus

Also known as RTC, Redtail cat, Red tail cat

FreshwaterFish

Redtail catfish (Phractocephalus hemioliopterus)
Mattia Nocciola · CC BY-SA 4.0

Care at a glance

Temperature
68–79°F
20–26°C
pH
6.0–7.5
Adult size
39.4 in
100 cm
Minimum tank
1,506 gal
5,700 L
Temperament
Aggressive
Social behavior
Solitary
Tankmates
With caution
Swim level
Bottom
Diet
Carnivore
Difficulty
Difficult
Breeding
No record
Rarity
Common
Family
Pimelodidae
Origin
Amazon and Orinoco basins

Overview

The redtail catfish is a huge, aggressive pimelodid, and it is not a fish for a normal home aquarium. Only an experienced keeper with a very large tank should take one on.

Did you know

The redtail catfish has a mouth wide enough to swallow prey nearly as large as its own head. In the wild it eats fish, crabs and whatever else it can get down. A small tank mate that looked safe one week can simply be gone the next.

Caring for the redtail catfish

Check your local rules before buying a redtail catfish, since it is restricted or banned in some places. Never release one into the wild.

It needs a cavernous tank of at least 1,506 gal (5,700 L). Oversized filtration has to keep up with the waste a fish this size makes. Use a bare bottom or large smooth pebbles, since it will swallow gravel that fits in its mouth. Skip planting and aquascaping, and give it open swimming room and rock solid water quality.

Keep the water warm and roughly neutral, at 68 to 79°F (20 to 26°C) and a pH of 6.0 to 7.5. Feed meaty foods like whole fish, shrimp and prepared pellets sized for large predators. Offer the food at the bottom, where it sits and waits.

Keep it alone or only with similarly huge fish. It is aggressive and territorial, and it will eat any tank mate small enough to fit in its enormous mouth. There is no reliable record of it breeding in home aquariums.

Good to know

The redtail catfish is a true monster in the family Pimelodidae, often 90 to 120 cm in captivity. It grows fast from the cute juvenile sold in stores, and the small size you buy is gone within a year or two. With the right space, it can live for many years.

In the wild

Redtail catfish come from the big main rivers and flooded forests of the Amazon and Orinoco basins. There they cruise the open bottom in slow, warm water.

From published sources

Tank mates

ScotCat and Aquarium Source keep the redtail catfish in a tank of its own.

Common questions

What size tank does a redtail catfish need?

A redtail catfish needs at least 1,506 gal (5,700 L). It spends most of its time in the bottom.

What temperature and pH does a redtail catfish need?

A redtail catfish is comfortable at 68–79°F (20–26°C) with a pH of 6.0–7.5.

What does a redtail catfish eat?

A redtail catfish eats meaty foods like whole fish, shrimp and prepared pellets sized for large predators. It will also eat any tank mate small enough to fit in its mouth.

How big does a redtail catfish get?

An adult redtail catfish reaches about 39.4 in (100 cm).

Can the redtail catfish live with other fish?

ScotCat and Aquarium Source keep the redtail catfish in a tank of its own.

Related species