Fig. 9. Total Na⁺/K⁺-ATPase content in all gill CC of F. heteroclitus acclimated to FW (blue diamonds), 1x SW (green circles), or 2.4x SW (red triangles) expressed as relative fluorescence units (RFU). (A) Time dependence of total Na⁺/K⁺-ATPase content at different salinity acclimation regimens (P<0.05; ^aFW vs. 1x SW, ^bFW vs. 2.4x SW, ^c1x SW vs. 2.4x SW). (B) Salinity-dependence of total Na⁺/K⁺-ATPase content after 5 weeks of acclimation. The data fit an exponential regression with r²=0.981. N=4 animals for each salinity and time.