Effects of fish bean (<i>Tephrosia vogelii</i>) leave extract exposed to freshwater Cichlid fish – <i>Tilapia zilli</i>

Abstract

This research was designed to investigate the effect of Tephrosia vogelii leaves extract on Tilapia zilli under laboratory conditions. The concentrations of the leaves extract used were 4.00, 2.00, 1.00, 0.50 and 0.25ml/l. The 96- hour LC50 was 0.71ml/l with lower and upper confidence limits of 0.31ml/l and 1.63ml/l respectively. The opercular ventilation and fin counts increased with an increase in the concentrations of the leaves extract at the end of 96- hour exposure period. Respiratory distress, loss of balance, settling at the bottom motionless and erratic swimming was observed before death during the exposure period. Histopathological examination of the gill, liver and kidney of the treated fish showed oedema of gill lamella and gill hyperplasia to vacuolation and necrosis of the liver cells while the kidney cells revealed a degeneration of kidney tubules. Phytochemical analysis of the leaves extract indicated the presence of alkaloid, tannin, saponin, cardiac glycoside, rotenone, steroids, balsam, phenol and volatile oil. The result of this study calls for the need to discourage the use of toxic plants for catching fish in Nigeria water bodies.