Water Quality Responses of Pureline Parental Crosses of Three African Catfish Species in Controlled Hatchery Systems

Abstract

The physicochemical water quality responses of pond systems stocked with pureline progenies of three African catfish species: Clarias gariepinus, Heterobranchus bidorsalis, and Heterobranchus longifilis was studied. The study, which used a perfectly randomized design with three replicates per treatment, aimed to investigate environmental tolerances and water-use dynamics among pureline crosses. Pureline progenies were grown in concrete hatchery tanks measuring 10 m × 10 m × 1.5 m for 120 days. Water quality indicators such as temperature, pH, dissolved oxygen (DO), alkalinity, turbidity, ammonia, phosphate, and biological oxygen demand (BOD) were measured using standardized procedures. The findings revealed that water temperature, turbidity, ammonia, phosphate, and BOD did not differ significantly (P>0.05) between treatments, indicating that these parameters are tolerated similarly among species. Significant differences (P<0.05) were seen in pH and DO levels, with H. longifilis crosses showing the greatest pH (8.90 ± 0.02) and DO (9.80 ± 0.02 mg/L), while C. gariepinus crosses showed the lowest values. Despite the differences, all measured metrics were within safe aquaculture limits. These data indicate that, while all three pureline catfish species can be cultivated under identical environmental circumstances, H. longifilis may have better physiological performance in terms of oxygen usage and pH tolerance. This research provides crucial baseline data for optimizing broodstock management and guiding species selection for site-specific aquaculture, particularly in systems where water quality control is a productivity constraint.