Isolation and quantitative determination of sex hormones in carps (Cyprinus carpio L.).

Changes in the oestrogen and progesterone level in the blood and ovarian tissue of mature carps from fish farms were examined using gas chromatographic method, before and after spawning as well as under wintering. Due to the high individual variation the observations cannot be regarded as quantitative. The highest oestrogen level was found before spawning, both in the ovaries and the blood, this level was somewhat lower after spawning and did not show any further change under wintering. The resting progesterone level had a low value, both in the ovaries and the blood, but it increased after spawning. The oestrogen concentration of blood was somewhat higher in the latter. Effect of pituitary extracts on changes of the sex hormone concentration in blood and ovary of wild carps was investigated too. The results of the hormone determinations, changes in body weights and "coefficients of maturity" are presented.