African sharptooth catfish

Quick facts

Adult size

80 cm, 5000 g typical harvest weight

Days to harvest

180 to 365 days from fingerling

Lifespan (max)

up to 12 years

Diet

omnivore

Temperature class

warm-water

Difficulty

beginner

Water parameters

Temperature range

12–35°C (optimum 27°C)

pH

6 to 9

Hardness

2 to 30 dGH

Minimum tank

500 L per individual at harvest size

Feed and growth

Feed protein

35% target

Daily feed (warm water)

2.00% of body weight per day

Daily feed (cool water)

0.70% of body weight per day

Max stocking density

80 g per litre of system water

A 5000g adult eats about 100.0 g of feed per day at optimum temperature. For a roster of 10 fish at adult size, that's around 1000 g of feed daily.

Legality

Aquaculture and possession rules vary by jurisdiction and change over time. This table reflects regulations as of the verified date on each row. Verify with your local fisheries or wildlife authority before stocking.

Jurisdictions not listed here default to "check local regulations". A non-listing is not a green light; rules in your specific county or municipality may apply.

Habitat and origin

Native to virtually all freshwater habitats across Africa, from the Nile to the Cape, plus parts of the Middle East and Southeast Asia (introduced). The species (Clarias gariepinus) is an air-breathing catfish with a labyrinth-like suprabranchial organ that allows it to survive in near-anoxic water and even crawl short distances across damp land between pools. This air-breathing ability makes it extraordinarily resilient in culture conditions. Adults grow large: 1–1.5 m and 10–60 kg in the wild, though culture size is typically 0.5–2 kg at harvest. The species is the most widely farmed catfish in Africa and a major aquaculture species in Southeast Asia (particularly the Netherlands, where it's grown in recirculating systems, and in Nigeria, which produces over 300,000 tonnes annually). The flesh is firm, mild, and boneless in larger specimens.

Climate and outdoor ponds

Climate classification

tropical (needs warm water year-round)

Outdoor pond zones (USDA)

9 to 13 (winter low around -7°C or warmer)

Heating in a temperate climate

Required for year-round operation

Cooling in a temperate climate

Not required

Zone bounds reflect year-round outdoor pond viability with no active heating. Anywhere outside the bounded zone, the species can still be kept in an indoor heated tank or a seasonally-managed system. Verify your specific microclimate, as a sheltered yard zone can run a half-zone warmer than the regional rating.

Care notes

One of the hardiest aquaculture species on the planet. African sharptooth catfish tolerate dissolved oxygen below 0.5 mg/L (they gulp air at the surface), ammonia levels that would kill most fish, pH from 5 to 10, and temperatures from 12°C to 35°C. This makes them nearly impossible to kill through water quality failures, which is appealing for aquaponics beginners. Growth is fast: 500–1 g in 6-8 months on commercial catfish pellet (32-38% protein). FCR is 1.0-1.5, among the best in freshwater aquaculture. Stocking density can be extremely high (50-100 g/L in recirculating systems with adequate filtration) because they tolerate crowding exceptionally well. Feed: sinking pellet, 32-38% protein. They eat anything organic, including dead fish, which simplifies mortality management. The main regulatory issue is invasiveness: Clarias gariepinus is prohibited in many US states, all of Australia, and parts of Europe because escaped fish establish feral populations that devastate native ecosystems. The air-breathing ability means they can migrate overland during rain, making containment difficult. Check local regulations carefully. Where legal, they're arguably the most productive and forgiving aquaponics fish available.

Further reading

• Aquaponics water chemistry: balancing pH for fish and plants
• Fish for aquaponics: tilapia vs everything else