Observations on fattening, growth and sex reversal of the greasy grouper Epinephelus tauvina (Forskal)

This paper deals with the experiments conducted on the development of broodstock, rearing ojjlngerlings and sex conversion of the greasy grouper, Epinephelus tauvina under controlled conditions. Groupers coUectedfrom the wild and harvested from the culture ponds were raised to broodstock in 10 x 5 X 2.3 m (net water capacity of 100 tons) R.C.C. tanks by feeding with freshly killed sardines, cod liver oil and vitamin tablets. E^erimental rearing ofjmgerluigs was carried out in 30 ton tank. In broodstock rearing, the growth rate variedfrom 10.1 mm/ 106.8g to 13.1mm/178.3g Jor the wild and 16.6mm/116.8g to 21.1mm/271.5g for the pond harvested stock with a feed conversion ratio of 4.6-7.7 and 3.2-3.5 respectively. Maximum growth increments of 27.2mm/404g and 25.5nvn/305g have been realisedfor the wild and pond harvested stock respectively. In general, pond harvested groupers showed higher growth with less conversion ratio. The fingerlings registered a growth rate of24mm/42g with a conversion ratio of 10. Preliminary experiments on sex reversal using androgen hornvone (Testoviron Depot containing Testosterone Enanthate) revealed the possibility of converting female to male by the indication of regression in ovary size and disappearance of oocytes