Hybrid catfish
Clarias macrocephalus × Clarias gariepinus
Also known asHybrid walking catfish · Big Ui (Thai) · Pla duk bic
Water parameters
Minimum tank: 600 L per individual at harvest size.
Feed and growth
- Feed protein
- 35% target
- Daily feed (warm)
- 2.50% of body weight
- Daily feed (cool)
- 0.50% of body weight
- Max density
- 100 g per litre
A 2500 g adult eats about 62.5 g of feed per day at optimum. 10 fish at adult size: ~625 g daily.
Legality
Rules vary by jurisdiction and change over time. Verify with your local fisheries or wildlife authority before stocking.
| Jurisdiction | Status | Notes |
|---|---|---|
| United States (federal) | prohibited | C. gariepinus parent line is Lacey Act injurious; hybrid inherits same restrictions verified 2026-05-13 |
| Queensland | prohibited | verified 2026-05-13 |
| European Union (bloc) | check local regulations | verified 2026-05-13 |
Unlisted jurisdictions default to "check local regulations".
Origin and habitat
This is the hybrid Clarias catfish, a cross of the Thai walking catfish (Clarias macrocephalus, used as the female parent) with the African sharptooth catfish (Clarias gariepinus, the male parent), made by artificial spawning. Developed in Thailand around 1988, it now makes up more than ninety percent of Clarias production there, on the order of fifty thousand tonnes a year, and is one of the most farmed freshwater fish in Southeast Asia. The hybrid pairs the fast growth, hardiness, and disease resistance of the African parent with the better flesh quality of the native Asian walking catfish, whose pure form grows too slowly and falls to disease too readily to farm well on its own. Like both parents it is an air-breather, gulping atmospheric oxygen through an accessory organ, which lets it survive in warm, foul, low-oxygen water and at very high stocking densities. The flesh is white, firm, and mild. Escaped and released hybrids interbreed with wild C. macrocephalus, and this genetic introgression is a recognized threat to the native species across Thailand.
Climate and outdoor ponds
- Climate
- tropical (needs warm water year-round)
- USDA zones
- 10–13 (winter low around -1°C or warmer)
- Heating needed
- yes
- Cooling needed
- no
Care notes
A tough, fast-growing tropical catfish and a mainstay of Southeast Asian pond farming. It grows to a harvest size of 500–800 g in roughly six to nine months in warm water, best around 26–30°C within a tolerated range of about 20–32°C. It eats a broad omnivorous diet and does best on a fairly high-protein feed, around 35 to 40 percent; reported feed conversion varies widely with diet and system, often in the 1 to 2 range on good pellet. Its great advantage for aquaponics is resilience: as an air-breather it shrugs off the low oxygen and crowding that would kill most fish, so it can be stocked very densely, well above most species. The hybrid does not breed true and is produced only by controlled artificial spawning of the two parent species, so a grower buys fresh fingerlings each cycle rather than relying on natural reproduction, which conveniently rules out the runaway breeding that plagues tilapia. Disease still matters: enteric septicemia from Edwardsiella ictaluri has caused losses in farmed hybrids. The major constraint outside Southeast Asia is legality: the African parent, Clarias gariepinus, is a Lacey Act injurious species in the United States, and the hybrid is restricted accordingly, with bans in parts of Australia and limits elsewhere, so it should not be raised where it could escape into warm waterways.