Effects of Crude Leaf Extract of Moringa Oleifera (L.) on the Cichlid, Oreochromis Niloticus (L.)
The effects of crude leaf extract of Moringa oleifera (L.) on Oreochromis niloticus (L.) fingerlings was investigated under static bioassay. A stock solution (0.25 mg/L) of the toxicant was prepared from which the various concentrations (40.00, 20.00, 10.00, 5.00, and 2.50 mg/L) of the crude leaf extracts were obtained, while 0.00 mg/L served as the control. The 96-hr LC50 of the leaf extract to the test fish was 8.13 mg/L, with upper and lower confidence limits of 18.39 and 3.59 mg/L respectively. The behavioral responses were characterized by loss of balance, air gulping and erratic swimming, yawning and pitching finally cumulating to death. Opercula ventilation rate was dose-dependent. Similar trend was recorded in the mortality rate with decrease in test material inclusion. Histopathological alterations were characterized by severe gill edema, hyperplasia of primary and secondary gill lamellae, while the liver cells showed hypertrophy, hyperplasia, vacuolization and necrosis, with no apparent changes in the control group. The implications of the findings are discussed in relation to the exposed fish.