EFFECTS OF ELECTROSHOCK, AIR EXPOSURE, AND FORCED EXERCISE ON SWIM PERFORMANCE IN RAINBOW-TROUT (ONCORHYNCHUS-MYKISS)

Swim performance of rainbow trout (Oncorhynchus mykiss) following forc ed exercise and pulsed DC electroshock both with and without subsequen t air exposure was examined. Swim stamina was assessed by exercising f ish at 39 cm/s until exhausted. Swim performance was impaired followin g all treatments. Increasing durations of air exposure (0-4 min) after electroshock resulted in progressively prolonged durations of swimmin g impairment (from 1 to 6 h). Electroshock reduced swimming stamina in a virtually identical fashion to that of 5 min of forced exercise. By comparison with the existing literature on the physiological effects of forced exercise, the impairment of swim performance most likely res ulted from a reduction in intracellular pH.