Weaning time in Clarias gariepinus (Burchell) larvae

Abstract

The present study attempts to assess for the African catfish, Clarias gariepinus (Burchell), the earliest possible weaning time from Artemia to crumbles of a commercial trout diet. At the onset of exogenous feeding, 24 aquaria were stocked with larvae, which were fed during varying periods with dried decapsulated cysts of Artemia. Depending upon the treatment group, the feeding of Artemia lasted 0, 2, 3, 5, 7 or 10 days. After these periods, the respective treatment groups were gradually weaned to the commercial diet. The experiment ended after 10 days of culture and the respective groups were compared on the basis of final weight, growth rate and survival rate. The final weights and growth rates of the groups weaned after 5 and 7 days did not differ significantly from the un-weaned group, attaining final weights between 70 and 76 mg and growth rates g between 0.31 and 0.32. The group receiving 100% Artemia feeding for only 2 days, attained a similar survival rate as the un-weaned control (96%). The data were fitted to a quadratic plateau model, which allowed the statistical assessment of the earliest possible weaning time. Survival and growth rate reached the plateau level when the larvae were gradually weaned after 1.8 and 4.1 days of Artemia feeding, respectively.