R. L. Smith

Respiratory energy requirements of the cod Gadus macrocephalus Tilesius relative to body size, food intake, and temperature

Measurements of oxygen consumption rates were made for both fed and unfed Pacific cod Gadus macrocephalus Tilesius at a variety of temperatures. Rates of oxygen consumption were found to be similar to those reported previously for Atlantic cod. At 6.5 °C, Vo2 was described by the equation ml O2 · ind−1 · h−1 = 0.158 (wet wt g0.078); r2 = 0.97. Increase in environmental temperature between 3.5 and 7°C resulted in a linear increase in rates of oxygen consumption. Between 7 and 12 °C, rates of oxygen consumption were similar. When fish were fed a single meal, oxygen consumption rates increased during the 1st and 2nd days after feeding, by ≈ 34 and 18%, respectively, over unfed rates. When fed daily, rates of oxygen consumption increased to peaks of 41–48% over unfed rates, depending on the temperature.