Histopathological alterations in the liver architecture of Mystus tengara exposed to sub-lethal concentrations of cypermethrin

Abstract

The application of cypermethrin in agriculture may reach the aquatic environment
through several routes including spray drift, surface runoff and ground water leaching and may
contaminate the aquatic systems. The present study aimed at assessing the toxicity of
cypermethrin in the liver histoarchitechture of Mystus tengara. Each of the 10 fish was stocked
into 12 PVC tanks containing 100 L dechlorinated tap water. Fish were exposed to three sublethal
concentrations of cypermethrin with one control (0, 0.026, 0.052 and 0.104 ppm) for 7, 14
and 28 days. Each of the control and treatment was maintained in three replicates. Results
showed the histopathological alterations including cloudy swelling of hepatocytes, necrosis,
vacuoles, hepatic cell rupture, karyolysis, nuclear pyknosis and degeneration of hepatic cells
exposed to different sub-lethal concentrations at different sampling dates. The present study
revealed that low levels (0.052 ppm) of cypermethrin exposure in the aquatic environment may
cause histopathological alterations in the liver of M. tengara, however, studies should be carried
out to understand the underlying mechanisms involved in long-term toxicity profile of
cypermethrin.