Vitellogenesis of Giant Gourami (Osphronemus goramy) Examined by the Measurement of Estradiol-17ß, Vitellogenin Concentration and the Size of Ovary

This study aims at observing the rate of estradiol-17ß synthesis on vitellogenin and the ovary size of the Giant gourami broodstock candidates and female broodstock. The female broodstock candidates were reared in a pond, while the female broodstock were reared in several ponds with the male broodstock (2:1). The blood sample taking was done every week during the three-week observation. The purpose is to measure the concentration of estradiol-17ß and vitellogenin. The observation on the broodstock candidates and the broodstock's ovary size was done in the last week of the observation using veterinary ultrasound. Most of the estradiol-17ß synthesis on the broodstock candidates is for vitellogenesis on the initial cycle of reproduction to reach maturation. In contrary, most of estradiol-17ß synthesis on the female broodstock is not for vitellogenesis in the next spawning cycle. The observation shows that the size of the broodstock candidates and broodstock's ovary is small.