Effect of Mechanical Water Filtration Techniques on the Epidemiological and Zootechnical Characteristics of Clarias gariepinus (Burchell, 1822) Farming

Abstract

Background: Mechanical filtration of aquaculture water is an alternative to chemical products used to combat fish infections. Aim: This study aimed to evaluate the effect of mechanical water filtration techniques on the epidemiological and zootechnical characteristics (EZC) of Clarias gariepinus. Methodology: A total of 240 specimens, free of any ailments and with an average weight of 10±03g, were distributed in triplicate among four treatments: T1 (no filtration system), T2 (1 layer of net), T3 (2 layers of net), and T4 (1 layer of net + 1 layer of gravel + 1 layer of sand), with 20 fish per experimental unit. Fish were reared for 105 days. Results: The EZC evaluation showed two clinical signs (trauma and inflammation). Overall, skin trauma was approximately 107 times more significantly represented than opercular trauma. The proportion of fish showing at least one ailment was very low (<10%) and varied non-significantly from 2.59% (T4) to 9.66% (T1). The condition factor was < 1 and was comparable (p > 0.05) between treatments. The mortality rate was high (> 5%) and more pronounced in the absence of a water filtration system. The average daily weight gain (1.560±0.468 g/day) and productivity (3.468±2.041 kg/m³/day) were comparable (p > 0.05) but higher in T1, while the production cost per kilogram of fish (0.37$/kg) was lower in T2 (p = 0.107). Conclusion: The EZC varied with the mechanical water filtration techniques but no significant difference was observed.