Fig. 1. (A) Na⁺/K⁺-ATPase activity increased in the gills of killifish after transfer from brackish water (BW; 10% seawater; grey bars) to seawater (SW; black bars). (B) Activity appeared to increase by a similar magnitude in the opercular epithelium, but this was not significant. Data are expressed as means ± s.e.m. (N shown within each bar). ^*Significantly different from pre-transfer (Pre) brackish water control (assessed using a post-hoc test; P0.05).