Chronic mercuric chloride intoxication in digestive system of Channa punctatus.

The effect of exposure to a sublethal concentration (0.30 mg/l) of mercuric chloride on the activities of alkaline phosphatase, acid phosphatase, amylase, trypsin, and pepsin has been examined at intervals of 7, 15, and 30 d in the digestive system of a teleost fish, Channa punctatus. Inhibition of the activities of all these enzymes was noted after the first week of treatment. Treatment of the fish for 15 d resulted in marked increases in the activities of all the enzymes. A slight fall in enzyme activity was recorded after 30 d, but the overall activity was higher than in control fish.