Studies on cyclic changes (for 12 months) in aquatic, aerial and total oxygen uptake in a fresh water air breathing fish, Channa marulius (Ham.) were made which showed wide range of variations in different months of the year. It ranged from a minimum value of 0.838, 0.283 and 1.121 m102/h in December to a maximum value of 2.888, 2.363 and 5.251 m102/h respectively in the month of June. Statistically significant correlation was observed between seasonal variations in oxygen uptake and seasonal changes in ambient water temperature but the points on a plot gave good fit to two regression lines, inflection at the meeting point of the two regression line was observed at 29.20C in this fish. The details have been discussed in this paper.