Diurnal rhythm of oxygen consumption and effects of body weight and water temperature on oxygen consumption rate of Sparus macrocephalus

The diurnal rhythm of oxygen consumption and effects of body weight and temperature on oxygen consumption rate of Sparus macrocephalus were examined under a flowing-water apparatus. The results revealed that the oxygen consumption rate of S.macrocephalus exhibits an increase with the rise of water temperature but a decrease with the increment of body weight. The rate of oxygen consumption varied with the alternation of day and night. The highest oxygen consumption rate was 3.16±0.26 μg·(g·min)^-1 at 11: 00pm, and the lowest oxygen consumption rate 0.74±0.59 μg·(g·min)^-1 at 7: 00am. The mean oxygen consumption rate was 1.98±0.84 μg·(g·min)^-1 at day and 1.96±0.63 μg·(g·min)^-1 at night. The results showed that the change of metabolism level of S.macrocephalus is not significantly between day and night (n=10, t=0.034 < t_0.05)。