African catfish dominate aquaculture in Nigeria. However, despite the wide acceptability of Clarias gariepinus, its full aquaculture potential has not yet been realized. High mortality in the fingerling stage and the resulting seed scarcity is a major problem. One probable cause of fingerlings mortality is disease infection. Successful treatment of diseases depends on selecting the most effective therapeutic drug or chemical and applying it in the most appropriate legal manner. This research was conducted to determine the effects of formalin, H2O2 and KMnO4 used as prophylactics on the growth performance and hematology of Clarias gariepinus.
Catfish fingerlings were treated with 2, 150, and 100 ppm of KMnO4, H2O2, and formalin respectively. After a 70-day culture period, growth, and haematological indices were measured. Data were subjected to one-way ANOVA and the mean were separated using the New Duncan Multiple range test at p ≤ 0.05.
Results indicated that fish treated with KMnO4 had the highest weight gain (5.31g) while the least (3.70g) was recorded in fish treated with H2O2. The control fish had the highest (1.91g) FCR while the least (1.47) was recorded in catfish fingerlings treated with KMnO4. White blood cells were more (6.23) in fish treated with formalin and lowest in control fish. Hb values were similar in control fish (12.45) and KMnO4 (13.09) treated fish. The least Hb was recorded in fish treated with formalin (10.52). Apart from PCV that decreased in fish treated with H2O2 and formalin, other red blood indices increased significantly.
Although all the used prophylactics had effects on growth and physiology of C. gariepinus fingerlings, KMnO4 appeared to have the least negative effect on the fish. The study therefore, recommends the use of potassium at 2 ppm for treatments in catfish fingerlings aquaculture.