Multiple organs damage in Channa punctatus when chronically exposed to mercuric chloride
In the present investigation, live specimens of Channa punctatus were collected, after acclimatization, they were chronically exposed to sublethal concentrations of mercuric chloride for 15 and 30 days. As compared to the control fish, Mercury treated fish kidney and liver showed marked histopathological changes. After 15 days the alterations detected initially were the widening of space between the capsule and the glomerular capillary network. The effect was dose and duration dependents. After 30 days of exposure, marked shrinkage of the glomerular tuft at all the concentrations were noticed. Further, the effect became so severe that visceral epithelium got ruptured, glomerulus got evacuated and necrosis of kidney tubule was seen. Elemental composition of the normal scales and scales of exposed fishes was also compared and it was found that fishes exposed to mercury, their scales have greatly reduced mineral composition.