Fish and experimental design
Sixty (60) O. niloticus apparently healthy with an average body weight 20 ± 0.09 g were obtained from the Abbassa Fish hatchery, Sharkia Province, Egypt. Fish were kept in two cement ponds (3 · 1 · 1 m) provided with an aerator for 2 weeks for acclimation before the start of the experiment.
Sharkia Province