Fig. 1. Twitch force and resting tension for ventricular preparations from yellowtail flounder (A) and Atlantic cod (B) exposed to oxygenated conditions () (flounder, N=6; cod, N=5) and to 35 min of anoxia followed by reoxygenation ([UNK]) (N=10, for both species). Arrows indicate times at which anoxia was induced (N₂) (20 min) and when preparations were reoxygenated (O₂) (55 min). `a' indicates significant difference between treatments. `b' indicates a significant decrease or increase from measurements within the treatment taken 5 min beforehand.