Effects of Circadian Rhythm on Aquatic and Aerial Oxygen Consumption in Freshwater Teleost, Channa gachua Ham

Usually behaviour and physiology of organisms are rhythmic in nature. The biological rhythm in oxygen consumption in air breathing fishes is interesting. The circadian rhythm has now become an inherent property of the system which they transmit even under artificial conditions of the laboratory. An attempt has been made to study the effect of circadian rhythm on aquatic and aerial oxygen consumption in freshwater teleost, Channa gachua. The maximum oxygen uptake from aquatic route was recorded in the early morning with moderately higher at noon and evening i.e., 54.74, 52.8, and 50.76 mL/kg/hr respectively. The highest rate of oxygen consumption from aerial route was observed in the morning, and noted as 85.61, 60.27 and 51.78 mL/kg/hr at noon and during evening period. Minimum oxygen uptake was recorded at mid night as 40.20 mL/kg/hr. The total oxygen consumption i.e., 140.35, 112.06 and 101.68 mL/kg/hr were recorded in the morning, afternoon and evening respectively. However, the minimum value of 85.54 mL/kg/hr was noted at mid night. It was found that percentage of aerial oxygen uptake in the morning, midday, evening and midnight was 60.985%, 53.41%, 52.92% and 46.9%. Circadian rhythm of the oxygen consumption has been correlated with diurnal fluctuation of metabolism of the ecosystem. The details have been discussed in this paper.