Growth Performance of Nile Tilapia (Oreochromis niloticus) at Different Stocking Densities in Concrete Tanks in Kaduna State

Stocking density is a critical management variable in intensive tilapia culture systems, influencing growth, feed efficiency, and fish welfare. This study evaluates the growth performance and survival of Nile tilapia fingerlings stocked at densities of 25, 50, 75, and 100 fish per cubic metre in concrete tanks at a research farm in Kaduna State, North West Nigeria. A total of 500 fingerlings with an initial mean weight of 8.3 g were distributed across 12 tanks and reared for ten weeks on a commercial tilapia pellet diet at 35% crude protein. Water quality was monitored biweekly, and fish were sampled fortnightly for weight measurement. Specific growth rate, weight gain, feed conversion ratio, condition factor, and survival rate were computed at the end of the trial. Results showed that fish stocked at 25 fish per cubic metre achieved the highest specific growth rate and lowest feed conversion ratio, while fish at 100 fish per cubic metre recorded significantly reduced growth and elevated ammonia concentrations. Survival rates did not differ significantly across density treatments, ranging from 91% to 96%. The study identifies 50 fish per cubic metre as the optimal economic stocking density for concrete tank tilapia production under the feed and management conditions representative of Kaduna State fish farms, balancing growth performance with land use efficiency.

Keywords: Oreochromis niloticus, stocking density, growth performance, concrete tanks, Kaduna State