A series of experimental studies indicated that copper as a toxicant causes a disturbance in enzyme activity. Stress conditions impose forced anaerobic conditions in the muscle, gill and hepatopancreas tissues of the crab Sesarma quadratum when exposed to two sublethal concentrations of 1/10 [2.8 ppm (Exp. 1)] and 1/3 [9.3 ppm (Exp. 2)] copper chloride for 21 d. Lactate dehydrogenase (LDH) activity was significantly elevated in muscle and hepatopancreas tissues whereas succinate dehydrogenase (SDH) activity was suppressed in the crab tissues of the muscle, gills and hepatopancreas for 21 d.

A series of experimental studies indicated that copper as a toxicant causes a disturbance in enzyme activity. Stress conditions impose forced anaerobic conditions in the muscle, gill and hepatopancreas tissues of the crab Sesarma quadratum when exposed to two sublethal concentrations of 1/10 [2.8 ppm (Exp. 1)] and 1/3 [9.3 ppm (Exp. 2)] copper chloride for 21 d. Lactate dehydrogenase (LDH) activity was significantly elevated in muscle and hepatopancreas tissues whereas succinate dehydrogenase (SDH) activity was suppressed in the crab tissues of the muscle, gills and hepatopancreas for 21 d.