Fig. 4. Band intensities of western blots of Na⁺/K⁺-ATPase (A) and Na⁺/K⁺/2Cl^– cotransporter (B) from the gills of lake trout, brook trout and Atlantic salmon kept in 0 p.p.t. (FW) and those transferred gradually and kept in 30 p.p.t. for 3 weeks (SW). Each value represents the mean ± s.e.m., N=4. Asterisks indicate significant differences between FW and SW values (P<0.05, Wilcoxon rank-sum test).