| The focus of this study was to identify and compare the physiological responses to exhaustive exercise in diploid and triploid brook trout. To quantify this, I measured plasma lactate, glucose and osmolality and white muscle energy stores (glycogen, phosphocreatine, and ATP) and muscle lactate before and immediately following exercise and during recovery at 2 and 4 hours post-exercise. In addition, oxygen consumption and ammonia excretion rates were determined before and after exercise. Overall, diploid and triploid trout showed similar metabolic responses (magnitude of change) to exercise. However, the time to recovery was faster in triploids for specific metabolites. Blood plasma osmolality, white muscle lactate, and white muscle ATP recovered earlier in triploids than in diploids. Oxygen consumption rates for triploids were significantly lower immediately following exercise but the time to recovery was the same as diploids. The results of this study suggest that larger cell size and greater number of chromosomes characteristic of triploidy affects neither the physiological response to, nor the ability of a triploid to recover from anaerobic exercise stress. These results lead to an investigation of the effects of chronic temperature (20°C) on the post-exercise recovery processes in diploid and triploid brook trout. For these experiments, I measured the same metabolic fuels as mentioned above following and during recovery from, exhaustive exercise. Exercise resulted in the typical physiological response for both triploid and diploid fish. In general, the physiological response and recovery patterns were similar between the two ploidies; however, survival was poor for the triploid fish. |
