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Preliminary studies on feminization and growth of Oreochromis spilurus (Günther) by oral administration of 17α‐ethynyloestradiol in sea water
Author(s) -
Ridha M. T.,
Lone K. P.
Publication year - 1995
Publication title -
aquaculture research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.646
H-Index - 89
eISSN - 1365-2109
pISSN - 1355-557X
DOI - 10.1111/j.1365-2109.1995.tb00938.x
Subject(s) - feminization (sociology) , biology , medicine , anabolism , endocrinology , hormone , body weight , zoology , sex reversal , oral administration , biochemistry , sociology , social science , gene
A study was conducted on Oreochromis spilurus (Günther) fry (9.0 mm) in sea water (38‐40%o) to evaluate the effects of three doses (40, 70 and 100 ppm) of a synthetic oestrogen, 17α‐ethynyloestradiol (17‐EE) on the feminization, specific growth rate (SGR), food conversion efficiency (FCE), condition factor (CF) and survival rate. The fry were fed a hormone‐impregnated diet for 42 days, followed by a hormone‐free diet for another 77 days. At the end of the experiment (119 days), successful feminization was obtained in all groups treated with 17‐EE. The dose of 100 ppm was the most potent one and induced 92.2% sex reversal. At the end of the hormone‐treatment phase (42 days), all groups treated with 17‐EE and the untreated controls showed no significant differences in growth, SGR, FCE, CF, and survival rate. After 119 days, a significant difference was detected only in the mean body weight and total length where the EE‐100 group had the highest values. However, this was due to the low survival rate in this group (37.5%) and not to any possible anabolic effect of 17‐EE. The findings of this study indicate that seawater sex reversal of O. spilurus is possible and 100% sex reversal could be achieved by slightly increasing the dose and/or duration of the treatment.