Chronic mercuric chloride intoxication in the digestive system of Channa punctatus.

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