Abstract:

The Nigerian aquaculture industry, despite its 50-year existence and vast cultivable water resources, still struggles to meet domestic ish demand, largely due to high feed costs. This study investigated the growth performance and physicochemical responses of Clarias gariepinus ingerlings fed graded levels (0%, 5%, 10%, and 20%) of Jatropha tanjorensis leaf meal (JTLM). Standard methodologies were used to assess the physicochemical qualities and growth parameters such as weight, lengths, speciic and daily growth rates, protein index, food conversion ratio and condition factor. The results revealed that the proximate composition of JTLM had moderate nutritional values: 25.5% crude protein, 5.0% ibre, 20.3% fat, 9.5% ash, 0.9% moisture, and 38.8% nitrogen-free extract. Water quality parameters remained within optimal ranges, with slight reductions in dissolved oxygen and increases in BOD, TSS, and conductivity at higher inclusion levels. Growth performance was signiicantly improved in the 5% and 10% JTLM groups, which exhibited superior weight gain, daily growth rate, speciic growth rate (SGR), and feed conversion ratio (FCR) compared to the control and 20% treatments. The best FCR was recorded in 5% (3.58) and 10% (3.52), and the Protein Index (PI) was also observed at these levels. Although all groups maintained healthy condition factors (>1.0), the 20% JTLM group had the lowest survival rate. Statistical analysis conirmed signiicant differences (p≤0.05) across treatments. The indings indicate that JTLM is a viable, cost-effective feed ingredient for African catish when used at appropriate inclusion levels. It is recommended to limit JTLM inclusion to 5–15%, combine it with high-protein ingredients, and further explore its effects on other cultured ish species.