To optimize species selection for riverine aquaculture on the Indus River, Pakistan, this study provides the first direct comparison of Nile tilapia and pangasius. The two species were reared in separate 100 m³ cages for 120 days under a high-water velocity (mean: 30 cm sec⁻¹) at three stocking densities: 15, 20, and 25 fish/m³. Nile tilapia (initial weight: 12.4 g) and pangasius (initial weight: 4.4 g) were evaluated for growth, physiological stress, and economic viability using two-way ANOVA and ANCOVA. Survival rates for both species were high (95-98%). A significant Species × Density interaction was found for most growth and physiological parameters. Final body weight declined with density for both species, reaching final stocking densities of approximately 4.5 kg/m³. Tilapia achieved its highest net yield (454.4 ± 7.7 kg/cage) only at the lowest density, while pangasius maintained a stable high yield (≈440 kg/cage) across densities. Physiologically, tilapia exhibited more pronounced stress at higher densities, with significantly higher serum glucose (P = .001). Economically, pangasius was profitable at 20 fish/m³ (BCR > 1.0), whereas tilapia was only profitable at 15 fish/m³. Pangasius is a more robust and economically suitable species for semi-intensive cage culture up to 20 fish/m³ in this system.
Rasheed et al. (Fri,) studied this question.