Fig. 1. (A) Bland-Altman plot comparing consecutive U_crit tests (U_crit1 and U_crit2) performed by rainbow trout, separated by a 40 min recovery period. Regression lines indicate the existence of two sub-groups, cold-acclimated (filled symbols) and warm-acclimated (open symbols) fish, based on the visible groupings in this graph. (B) U_crit1 versus ambient water temperature for rainbow trout. Fish are divided into two subgroups, cold-acclimated (filled symbols) and warm-acclimated (open symbols) fish. Regression: y=40.44+2.42x, r²=0.74; P<0.001. (C) U_crit2 versus U_crit1 for individual rainbow trout performing two U_crit tests separated by a 40 min recovery period. Fish are divided into cold-acclimated and warm-acclimated groups. The thin line is the line of identity where x=y, i.e. the predicted line if U_crit1=U_crit2 independent of temperature, and this was not the case. Regression (thick line): y=-204.3+7.57x-0.05x², r²=0.81, P<0.001. (D) Recovery ratios for individual rainbow trout as a function of acclimation temperature (filled symbols, cold-acclimated group; open symbols, warm-acclimated group). The regression line for these data illustrates that warm-acclimated fish could not attain the same U_crit after a 40 min recovery.