Fig. 5. The effects of exposure to hypercarbia (nominal PW_CO2=6 Torr; 1 Torr=133.3 Pa) and acetazolamide treatment (30 mg kg^-1) on branchial (A) net excretion of acidic equivalents (J_netH⁺), (B) titratable net acid flux (J_netTA) and (C) net ammonia excretion (J_netNH₃) in rainbow trout (Oncorhynchus mykiss). J_netH⁺ was calculated as the sum of J_netTA and J_netNH₃, signs considered. Data are mean values ± 1 s.e.m.; N=11 for both control and hypercarbia treatment groups. Data were analyzed by two-way RM ANOVA with treatment group (control versus hypercarbic) and sampling time [pre- or post-acetazolamide (Az) injection] as factors; P values are indicated on the figure. An asterisk (^*) indicates a significant difference as a result of Az injection within a treatment group, while a dagger () indicates a significant difference between control and hypercarbia treatment groups within a given sampling time. Where significant interactions did not occur, only the P values are indicated on the figure.