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In recent years, aquaculture of the African catfish Clarias gariepinus (Burchell 1882) has experienced rapid growth in Africa, Asia and Europe. In order to improve its rearing systems, it is imperative to determine the individual growth patterns of the species. Individual fish growth is relevant when evaluating commercial viability, planning the time of harvest or projecting profits. In this study, we analysed the growth data of African catfish juveniles reared in an indoor freshwater recirculation aquaculture system and fed five different commercial aquafeeds over a period of 111 days. We fitted five nonlinear growth models—von Bertalanffy, Gompertz, Brody, Richards and logistic—to the weight data and applied the Akaike information criterion, the sum of squares and the maximum likelihood to determine the model that best describes the growth data of the species under the controlled culture conditions. According to the goodness‐of‐fit criteria, the Gompertz model was consistently the one that best described the growth of African catfish. The F‐test showed significant differences (p = 0.05) for one of the experimental feeds (T1,2) that produced the superior growth in terms of rate and biomass.

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Two experimental feeding trials were conducted concurrently to study the growth response of African catfi sh Clarias gariepinus fi ngerlings to graded levels (0, 5, 10, 15 or 20%) of clupeids in Danish fi sh meal (DFM) based diets. Chemical analysis of the DFM and clupeids fi sh meal (CFM) was carried out. Completely randomized design with triplicated groups of fi ngerlings were used for both trials in an indoor and outdoor concrete tanks for six and twelve weeks respectively. The study aimed at achieving a cost effective fi sh meal from local aquatic resources (clupeids fi sh) highly prolifi c and abundant in Nigeria water bodies to replace foreign fi sh meal in West Africa Region. A project supported by West African Agricultural Productivity Project (WAAPP) in NIFFR, Nigeria. The results of proximate, amino acid profi le, mineral and fatty acid composition analysis of CFM indicated values which are very close to those of the DFM. The proximate analysis revealed CFM to contain 70.6% crude protein while DFM contains 72%. There were no signifi cant difference between the treatments with respect to fi nal weight, feed consumed, feed conversion ratio, digestibility and survival (P>0.05) although there was signifi cant difference in specifi c growth rate (P<0.05) with the highest value obtained in the diets with both fi sh meal at ratio 1:1. There were no signifi cant difference in haematological parameters (P>0.05). However the lymphocytes were high in all the groups which might not be particularly due to the treatments. The high proliferation of the body defence cells by the fi sh could be a mechanism of survival in the aqua-medium which is likely to be high in microbial load due to waste materials. Feed Cost/Kg for DFM was N260.16 while for CFM was N227.16. The results of chemical analysis and feeding trials indicated positive replacement of the DFM with CFM in fi sh feeds without negative effect on growth performance.