Overview
The redtail catfish is one of the giants of the Amazon River. As a baby it is cute, with a dark body, a white belly, and a bright orange-red tail, and pet shops sometimes sell it in a tiny tank. But do not be fooled: this fish grows into a monster four to five feet long and heavier than a grown adult person. It is famous among fish keepers as the ultimate tank buster.
In the wild the redtail catfish cruises the deep channels of the Amazon and Orinoco rivers, swallowing whole fish, crabs, and anything else it can fit in its huge mouth. Because it gets so enormous, it needs a tank bigger than most people could ever build at home, more like a small swimming pool. For that reason, it is really a fish for public aquariums and expert keepers with giant custom tanks, not for a normal bedroom aquarium.
| Care level | Expert only |
| Adult size | 4-5 ft (1.2-1.5 m) |
| Lifespan | 15-20+ years |
| Temperament | Predatory |
| Min. tank | 1,500+ gal (5,700+ L) |
| Temperature | 68-79 F (20-26 C) |
| pH | 5.5-7.0 |
| Diet | Carnivore |
| Schooling | No, kept alone |
A tiny baby that becomes a titan
The redtail catfish starts out just a few inches long, but it can grow more than a foot in its first year. In a few years it reaches the size of a large dog, then keeps going. This is why it is called a tank buster.
It needs a pool, not a tank
A full-grown redtail needs well over a thousand gallons of water, far more than almost any home aquarium holds. Most people simply cannot give it a big enough home, so it belongs in zoos and public aquariums.
A mouth like a bucket
This catfish is a hungry hunter that swallows prey whole. In the wild it eats fish, crabs, and fallen fruit, and it will try to eat any tankmate small enough to fit inside its very large mouth.
Please do not buy on impulse
Because babies look so sweet in the store, many people buy one without knowing how huge it gets. Then they cannot care for it. Always research a fish's grown-up size before bringing it home.
A long-lived river giant
Redtail catfish can live 15 to 20 years or even longer. Taking one on is a very big, very long commitment that only experts with huge custom tanks should make.
Fun facts
- Redtail catfish can grow four to five feet long.
- A full-grown one can weigh more than 100 pounds.
- They live in the Amazon and Orinoco rivers of South America.
- They swallow their food whole, including whole fish and crabs.
- They are nicknamed tank busters because they outgrow almost any home tank.
Frequently asked questions
Can I keep a redtail catfish at home?
Almost certainly not. It grows far too big for a normal home tank and needs a pool-sized aquarium of over a thousand gallons. It is really a fish for public aquariums.
How fast does it grow?
Very fast. It can grow more than a foot in its first year alone and keeps growing for years after that.
Why do stores sell such a big fish?
They sell them as cute babies, but many buyers do not realize how enormous they become. Always check a fish's adult size first.
What does a redtail catfish eat?
It is a hunter that swallows whole fish, crabs, and other prey. It will eat any tankmate that fits in its huge mouth.
