PERSPECTIVES ON CLARIID CATFISH CULTURE IN AFRICA

The African catfish Clarias gariepinus is undoubtedly the most suitabl e species for aquaculture throughout its distributional range. The rea sons for this, which relate principally to the biology and ecology of the species, are briefly reviewed and commented upon. The species is c urrently farmed on a commercial and subsistence basis in over 12 Afric an countries, the most important of which in terms of tonnage produced are Nigeria, South Africa, Zambia and Ghana. The scientific and techn ological foundation for the farming of African catfish is sound, and h as been developed mainly in The Netherlands, South Africa, Belgium and the Central African Republic. Most of the important culture parameter s, inclusive of spawning, incubation, larval nutrition and rearing, pr oduction and feed formulation have received adequate attention for the successful farming of the species in Africa, Production levels, depen ding on the type of operation, range from < 1 to 40 t/ha per year, and exceed 800 kg/m(3)/year under ultra-high density commercial culture c onditions. Food conversion ratios vary between 1:6 using agricultural waste, to 1:1.1 using formulated, least-cost feeds. Significant progre ss has also been made in the development of the technology for the far ming of a related species, Heterobranchus longifilis and the hybrid of this species with Clarias gariepinus. Despite the technological kow-h now, total recorded production of clariid catfish in Africa in 1993 wa s a mere ca. 4500 tonnes. Despite the fact that there may be a conside rable margin of error in the reported production figures the farming o f catfish in Africa is a marginal activity. The reasons for this are m anifold and can be primarily pinned on market forces, inadequate regio nal infrastructures, production costs, the socio-economics of fish far ming and the philosophy upon which aquaculture development in Africa i s largely based. Nevertheless the future potential for the farming of clariid catfish throughout their distributional ranges is immense.