ABSTRACT
Three different chemicals: fonnalin, hydrogen peroxide and potassium permanganate were used for intermittent prophylactic treatment of Clarias gariepinus fingerlings (2.43±0.04) for 10 weeks. The experiment was made up of four treatments: Tl (Control), T2 (Potassium permanganate at 2ppm concentration), T3 (Hydrogen peroxide at 1600ppm concentration), and T4 (Formalin at 100Oppm concentration) with each treatment having 15 fingerlings of catfish. Each treatment was in triplicates. The fish bath lasted for 30minutes. The process was repeated biweekly while some parameters such as mean weight gain, specific growth rate, daily weight gain, and percentage survival were taken weekly. Haematological parameters such as white blood cells, red blood cells, heamoglobin, Mean corpuscular heamoglobin concentration, mean corpuscular volume, and packed cell volume were analyzed. The histology of the liver and the gills were also carried out. The data were later subjected to one way analysis o!variance and the mean were separated using Duncan Multiple range test.
Mean final weight gains of 3.96±0.67, 5.31±1.66, 3.70±0.28, and 5.27±1.84 were recorded for treatments 1, 2, 3 and 4 respectively. The specific growth rate ranged between 0.57±0.06 and 0.68±0.14%/day, the Average Daily Weight Gain (g/day) between 0.05±0.01 and 0.08±0.02. The percentage survival is 72.33±11.45%, 56.00±4.81%, 61.91±2.38% and 45.22±10.02% for treatments 1, 2, 3 and 4 respectively.There were significant differences in the weight gain and the percentage survival of the experimental fish (p<0.05). The white blood cells count ranged between 4.13±0.32 and 6.23±0.25 from Tl to T4. The white blood cells count ranged between 9.20±9.40 and 27.60±0.88. The heamoglobin values were 12.45±2.03, 13.09±0.98, 11.34±1.76 and 10.52±3.04 for Tl, T2, TJ and T4 respectively. The highest MCV (356.85±2.45) was recorded in T4 and the lowest in Tl. Apart from PCV that decreased in values in T3 and T4, other red blood indices increased significantly (p<0.05) when compared to the control.
It was concluded that the three chemicals effected the growth, survival, haematology, and histology of C. gariepinus fingerlings. Good management practices that prevent disease infections in fish are better for fish farmers. However, if chemical is to be applied to treat diseas.e in fish, KMn0 4 is recommended as its negative effects on fish haematology and histology according to this study is the lowest when compared to the other chemicals.