Investigations on the Osmoregulation System of Freshwater Fish (Oreochromis niloticus) Exposed to Mercury in Differing Salinities

WOS: 000469274900008Increases in salinity affect fish physiology and metal uptake. Thus, freshwater fish Oreochromis niloticus were exposed to Hg2+ in different salinities (0, 1, 10 ppt) for acute (0,3 mu M Hg2+, 3 days) and chronic (0,03 mu M Hg2+, 30 days) exposure protocols. Following the exposures, activities of Na+/K+-ATPase, Mg2+-ATPase and Ca2+-ATPase in the gill and Ca2+-ATPase in muscle of fish were measured and significant (P<0.05) results were remarked. Salinity increase alone did not cause alterations in ATPase activities in the gill and muscle in both acute and chronic exposures. However, there were increases in ATPase activities in gill and muscle tissues of fish exposed to Hg2+ in different salinities both in acute and chronic exposures. In acute exposures, only Mg2+-ATPase activities in the gill increased at 1 and 10 ppt salinities (P