Fig. 11. White muscle PCr (A) pH_i (B), ATP (C) and lactate (D) levels from carp exposed to normoxia (N) and for up to 8 h exposure to hypoxia. Phosphocreatine levels are normalized to the sum of PCr and P_i. PCr, ATP and lactate levels are expressed relative to normoxic controls. The black horizontal bar above the x-axis indicates the period of hypoxia exposure (P_O2=20 Torr). Each point represents mean ± 1 s.d. Significant differences (P<0.05) between the resting/normoxic fish and hypoxia-exposed fish are indicated by an asterisk. From left to right, N=4, 10, 6, 3 and 4.