SEX HORMONES IN FISH. THE OESTROGENS OF COD (GADUS CALLARIAS)

Abstract

SUMMARY: Mature ova of cod have been found to contain oestradiol-17β in a concentration of approx. 4·8 μg./kg. corresponding to a weight of 5·3 μg./fish. Oestrone has been found in a concentration of 1 μg./kg. or approx. 1·1 μg./fish. Immature ova contain, at most, only traces of these compounds. No other phenolic steroids could be identified. The ovarian sac has been found to contain only oestradiol in a concentration corresponding to an approximate weight of 0·4 μg./fish. No oestrone or oestriol could be identified in the gonads of male cod; the trace in this organ of material resembling oestradiol was insufficient for identification.