EFFECTS OF CIRCADIAN RHYTHM ON AQUATIC AND AERIAL OXYGEN CONSUMPTION IN FRESH WATER TELEOST, CHANNA GACHUA

Abstract

Usually behavior and physiology of an organism are rhythmic in nature. The knowledge of biological rhythm of oxygen consumption in air breathing fish is scarce. The circadian rhythm has now become an inherent property of the system which they transmit even under artificial condition in the laboratory to study the effect of circadian rhythm on aquatic and aerial oxygen consumption in fresh water teleost, Channa gachua. The maximum oxygen uptake from aquatic route was recorded 54.74 (ml/kg/hr) in the early morning with moderately higher at noon and evening, i.e., 52.8, and 50.76 (ml/kg/hr) respectively. The highest rate of oxygen consumption from aerial route was observed in the morning as 85.61 (ml/kg/hr), while 60.27 and 51.78 (ml/kg/hr) at noon and evening respectively. Minimum oxygen uptake was recorded 40.20 (ml/kg/hr) at mid night. The total oxygen consumption, i.e., 140.35, 112.06 and 101.68 (ml/kg/hr) were recorded in the morning, afternoon and evening hours 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 recorded as 60.985%, 53.41%, 52.92% and 46.9%. Organisms physiology and behavior are often rhythmic and these rhythms will persist in the laboratory in the absence of photoperiod and various physicochemical factors of the environment in which organisms live under natural conditions. Circadian rhythm of the oxygen consumption has been correlated with diurnal fluctuation of metabolism of the ecosystem.

 

Keywords: Circadian rhythm, oxygen consumption, Channa gachua.