Perspectives on clariid catfish culture in Africa

Abstract

The African catfish Clarias gariepinus is undoubtedly the most suitable species for aquaculture throughout its distributional range. The reasons for this. which relate principally to the biology and ecology of the species, are briefly reviewed and commented upon. the species is currently farmed on a commercial and subsistence basis in over 12 African countries, the most important of which in terms of tonnage produced are Nigeria, South Africa, Zambia and Chana. The scientific and technological foundation for the farming of African catfish is sound. and has been developed mainly in The Netherlands, SouthAfrica, Belgium and the Central African Republic. Most of the important culture parameters, inclusive of spawning, incubation, larval nutrition and rearing, production and feed formulation have received adequate attention for the successful farming of the species in Africa. Production levels. depending on the type of operation, range from < 1 to 40 t/ha per year, and exceed 800 kg/m³/year under ultra-high density commercial culture conditions. Food conversion ratios vary between 1:6 using agricultural waste, to 1:1.1 using formulated, least-cost feeds. Significant progress has also been made in the development of the technology for the farming of a related species, Heterobranchus longifilis and the hybrid of thisspecies with Clarias gariepinus. Despite the technological kow-hnow, total recorded production of clariid catfish in Africa in 1993 was a mere ca. 4500 tonnes. Despite the fact that there may be a considerable margin of error in the reported production figures the farming of catfish in Africa is a marginal activity. The reasons for this are manifold and can be primarily pinned on market forces. inadequate regional infrastructures, production costs, the socio-economics of fish farming and the philosophy upon which aquaculture development in Africa is largely based. Nevertheless the future potential for the farming of clariid catfish throughout their distributional ranges is immense.