POSSIBLE MORTALITY AND NEPHROSIS IN Clarias gariepinus (Burchell, 1822) EXPOSED TO ETHANOL LEAF EXTRACTS OF Senna occidentalis (L.)

Abstract

Clarias gariepinus juveniles (250) were stocked; from which 96 fish samples were randomly deployed for range-finding
test, while 108 were for the main experiment using 12 plastic tanks of 35 L (4 treatments and 3 replicates), containing 8

fish/tank and 9 fish/tank respectively, filled with 10 L of water. Sub-acute renewal bioassay method was adopted. Range-
finding test were done using Senna occidentalis ethanol leaf extracts of 1.00, 1.50, and 2.00 g/ 25 cl of distilled water for

120 hours, followed by the main experiment which had three concentrations of 3.00, 5.00, and 7.00 g/ 25 cl of ethanol leaf
extract of S. occidentalis prepared. Daily doses of 5 ml syringes were administered in each treatment for 23 days. The fish
were fed twice daily, dead fish in each tank were recorded. The increase in concentrations followed the no-effect
observation of the 1.00, 1.50, and 2.00 g/ 25 cl used for the range-finding test. Analysis of variance were used to assess the
data. The mortality rate significantly (p < 0.05) varied across the main experiment's treatments and increased with
increased concentrations. Treatment A (control) showed no visible lesion, treatment B (3.00 g/ 25 cl) showed vacuolation
of the epithelial lining's cytoplasm, treatment C (5.00 g/ 25 cl) showed moderate tubular epithelial necrosis, and treatment
D (7.00 g/ 25 cl) showed both glomerular and tubular epithelial necrosis. The toxicity tolerance of C. gariepinus showed
that the degree of damage observed increased with an increase in the concentration of S. occidentalis.