Impact of Coal Mine Water on the Histology of Liver of Clarias batrachus (Linnaeus, 1758)

Abstract

Aim: Increased instances of mining to obtain various sorts of minerals and energy forms have been reported to impose serious ill effects on the environment. Coal is one such energy form which is being extensively mined in the regions of Jharkhand. The following experiment was designed to investigate the effect of coal mine water on the histology of liver of Clarias batrachus. Study Design:  Fish were randomly divided into 3 groups with 5 fishes in each. Group 1 was kept as control, whereas fish in group 2 and 3 were exposed to 65% V/V of coal mine water collected from Pachwara North coal mines, Pakur, Jharkhand for 21 and 30 days, respectively. Place and Duration of Study: The study was conducted in the Department of Zoology, St. Xavier College, Ranchi during March 2025 to May 2025. Methodology: After 21 and 30 days, fish were sacrificed and liver tissues were procured, blotted free of blood and fixed in Bouin’s solution. The tissues were dehydrated, cleared and embedded into paraffin blocks. 5µm thin sections were cut and stained with H&E stain following routine laboratory protocol. Photomicrography was done using image analyzer for comparative analysis. Results: Control liver showed normal architecture of intact central vein, roughly hexagonal hepatocytes with centrally placed nucleus alternating with sinusoids of normal diameter. In the treated group for 21 days, congested central vein, vacuolization and irregular sinusoids were notably visible. The damage intensified on exposure for 30 days showing time-dependent increase in the histological damage. Conclusion: This showed that there were observable alterations in the liver histology upon exposure to coal mine water and the degree of damage intensified as duration of exposure increased. This warrants effective management of coal mine effluents prior to its disposal in the water bodies.