An attempt is made to study the oxygen consumption, CO
2 output and the nitrogen excretion of the freshwater mullet
Rhinomugil corsula. It is found that whereas the O
2 consumption, the CO
2 output and the respiratory quotient decreased with increase in the duration of exercise, the NH
3-N and total-N excretion showed the opposite trend.
Keywords Oxygen consumption - nitrogen excretion - freshwater mullet - carbondioxide output