The rate of oxygen consumption of plaice increases after feeding and declines to a resting level after 24–72 h. The maximum increase corresponds to a level which is approximately twice the resting rate of oxygen consumption. This increase corresponds to the Specific Dynamic Action (SDA) and increases in magnitude with increase in food intake. The magnitude is greatest with high protein content diets. The duration of the SDA effect is reduced with increase in temperature and increases with the percentage of protein in the diet.