Histopathological Alterations In Organs of Nile Tilapia Fingerlings Exposed To Sub-Lethal Concentrations of Aqueous Crude Leaves Extract of Desert Date

Abstract

Background: Histopathological changes have been widely used as biomarkers in determining the effects of pollutants on fish. Leaves of Balanites aegyptiaca, a deep-rooted, evergreen or semi-deciduous, multi-branched, spiny tree have been reported to have pesticidal, anaesthetic and ichthyotoxic effects. This study sought to find out the effect of sub-lethal concentrations (5.00, 11.00, 21.00, 43.00, and 86.00 mg/L) of B. aegyptiaca on histopathology of gills, kidney, and liver of mixed-sex Oreochromis niloticus fingerlings Methods: A total of 120 O. niloticus fingerlings (mean weight 23±0.03 g and mean total length 12.50±0.39 cm) were exposed to aqueous crude leaves extract of B. aegyptiaca. The gills, kidney, and liver were excised and processed routinely for the elucidation of histopathological changes Results: Dose-dependent histopathological changes were observed in the three organs (gills, kidney and liver) of O. niloticus exposed to graded concentrations of B. aegyptiaca. Gills showed moderate to severe secondary lamellae fusion, desquamation, and primary lamellae congestion while the kidney displayed mild to severe renal tubular epithelial cell degeneration and necrosis as well as pigmentation of renal tissues. The liver showed varying degrees of histo-architectural alterations such as hepatocellular degeneration and necrosis, cellular infiltrations, kupffer cell proliferation, portal, and sinusoidal congestions Conclusion: Owing to these histological alterations in the gills, kidney, and liver observed in this study, prolonged exposure of fish to B. aegyptiaca should be discouraged to preserve fish diversity