Bioenergetics, exercise, and fatty acids of fish

Abstract

The bioenergetic aspects of pentachlorophenol poisoning and exercise in fish are discussed. When cichlids are exposed to 0.2 ppm of pentachlorophenol, the intake of food was increased and energy losses were also increased. Growth was decreased. The cost of specific dynamic action was higher and the cost of exercise was increased above the cost of similar exercise in nonpoisoned controls. In salmon swimming to exhaustion at 52 cm/sec fatty acids 18:1, 16:0, and 16:1, and at 59 cm/sec fatty acids 22:6, 18:2, and 20:4 suffered the greatest depletion. At 52 and 59 cm/sec, respectively, average exhaustion times were 1141 and 398 minutes; the equivalents of distance traveled were 26.0 and 12.7 miles; the loss in lipids, 54 and 10 mg; and the average weight losses, 830 and 480 mg per salmon. Total caloric losses calculated from the data on lipid and weight losses were approximately 1118 and 566 calories. Calculated from the data of Brett (1964) on O2 consumption, caloric losses were estimated at only 344 and 188 calories. The difference between observed values and values calculated from the data of Brett may lie in the duration and severity of the exercise. Brett collected his data on O2 consumption on the basis of at most two hours at high velocity. Possibly when maximum effort is involved each succeeding mile and each succeeding hour is more difficult and more costly to the salmon. © 1968 by the American Society of Zoologists.