Effect of gonadal steroids on respiratory metabolism of Anabas testudineus (Bloch).

The present investigation deals with the effect of gonadal steroids on the oxygen consumption (through gills only) in an air breathing fish, Anabas testudineus (Bloch). A good correlation (P less than 0.05) has been established between the seasonal variations in VO2 and cyclic changes in the activity of gonads in both the sexes. Oxygen consumption in both the sexes of A. testudineus were studied for a period of fourteen months. VO2 of male Anabas remained higher as compared to female throughout the period of investigation. Statistical as well as experimental analysis of the data also indicates that the "male hormones" are much more effective in bringing about the homeostasis of oxidative metabolism as compared to "female hormone" in this fish. The treatment with testosterone brings about significant (P less than 0.001) increase in VO2 in males though the lower dose proved to be most effective. Most of the "female hormones" (progesterone, Duogynon forte and Ovocyclin) used in the present investigation seem to decrease the VO2 significantly in females. The decrease in VO2 was more pronounced at higher dosage. Two peaks of VO2--first in June/July and second in October--have also been observed in this fish. The reason for and mechanism of such change are discussed in the present investigation.