African Catfish Farming: A Production Guide

How African catfish (Clarias gariepinus) is farmed: air-breathing biology and extreme density tolerance, RAS and pond culture, induced spawning, fast growth and harvest.

Overview

The African or sharptooth catfish (Clarias gariepinus) is a hardy, fast-growing food fish of the family Clariidae, the air-breathing catfishes, native throughout Africa and the Middle East. It is farmed in Africa, in intensive recirculating systems in the Netherlands, and across Southeast Asia. Its defining feature is an accessory air-breathing organ, which lets it survive in low-oxygen water and at extremely high stocking densities.

Air-breathing biology and tolerance

Clarias gariepinus has large accessory breathing organs made of modified gill arches, allowing it to take oxygen directly from the air. This makes it exceptionally tolerant of poor water quality and crowding, so it can be raised at densities that would suffocate most other fish. It is a large, omnivorous and voracious predator, reaching adult lengths of about 1 to 1.5 m and up to roughly 60 kg, eating both live and dead animal matter as well as plant material.

Culture systems

• Ponds: widely used in Africa and Asia, often at high stocking because of the air-breathing habit.
• Recirculating aquaculture systems (RAS): the basis of intensive production in the Netherlands, with dozens of farms established since the species was introduced there in 1977.
• Tanks and concrete systems: used for intensive grow-out where water is reused.
• Biofloc systems: also applied, suiting the fish's tolerance of high density.

Water temperature and feeding

African catfish grows well in warm water, with temperatures of about 26 to 32 °C reported as satisfactory for growth. It is fed formulated pelleted diets in intensive culture and grows quickly; FAO grow-out guidance describes stocking of roughly 2 to 10 fingerlings per square metre giving a marketable size of about 200 to 500 g after around six months, with higher densities discouraged because end-of-cycle water quality becomes hard to manage.

Reproduction and seed supply

African catfish does not spawn readily in captivity, so hatcheries rely on artificial reproduction. FAO describes inducing mature broodstock with hormone injection (carp pituitary extract or human chorionic gonadotropin), then stripping the eggs and milt and fertilizing them by the dry method, followed by incubation and larval rearing. The fish is also crossed with Heterobranchus to produce hybrids used in some farming systems.

Growth, harvest and diseases

Because of its fast growth and tolerance, African catfish reaches market size within months and is harvested from ponds by netting or draining, or removed from tanks in intensive systems. Its hardiness makes it relatively robust, but under crowding and poor water quality it is affected by bacterial infections such as motile aeromonad disease and by parasites, so even in high-density systems water management and biosecurity remain important.