Fig. 1. On-line venous blood oxygen partial pressure (Pv_O2) measurements in the ductus Cuvier of cold-acclimated and warm-acclimated rainbow trout (A,D) during the post-operative recovery period, (B,E) following the first swim test and (C,F) following the second swim test. Mean values (black line; grey lines are the S.E.M.) were derived by pooling data for all fish as a function of time. 1 torr=133.3 Pa.