Histopathological changes in the gill and liver of <i>Clarias gariepinus</i> exposed to acute concentrations of <i>Vernonia amygdalina</i>

Abstract

Vernonia amygdalina is a tropical African woody shrub with diverse phytochemical constituents recently linked with insecticidal properties that could replace the harmful agrochemical pesticide usage around aquatic environment. This study investigates the histopathological changes in the liver and gills of Clarias gariepinus exposed to acute toxic concentrations of V. amygdalina. C. gariepinus juveniles of varied weight (7.28 ± 0.03 g) and length (4.82 ± 0.06 cm) were exposed to graded aqueous concentrations (0.188, 0.375, 0.75, 1.50 and 3.00 g/l) of V. amygdalina. The varied concentrations of V. amygdalina precipitated varied dose-dependent histopathological distortions in the hepatic (central venous congestion and hepatocellular degeneration) and gill parenchyma (lamellar hyperplasia, clubbing and occluded inter-lamellar space) of exposed C. gariepinus. The liver (hepatocyte nuclear diameter and surface area) and gill (secondary lamellar length, width, interlamellar distance and surface area) morphometrics were strikingly altered varied concentrations of V. amygdalina. V. amygdalina seems to be toxic to fish and therefore has to be cautiously applied when used as insecticides to control unwanted organisms around the fish habitats.

Keywords: Vernonia amygdalina, Clarias gariepinus, Histopathology, Liver, Gill