TY  - JOUR
T1  - Effects of Oral Administration of Estradiol Valerate on Gonadal Sex Differentiation in the Rainbow Trout, <I>Oncorhynchus mykiss</I>
AU - , Senol Guzel AU - , Mecit Yoruk AU - , Kenan Gullu AU - , Turan Karaca 
JO  - Journal of Animal and Veterinary Advances
VL  - 7
IS  - 11
SP  - 1400
EP  - 1404
PY  - 2008
DA  - 2001/08/19
SN  - 1680-5593
DO  - javaa.2008.1400.1404
UR  - https://makhillpublications.co/view-article.php?doi=javaa.2008.1400.1404
KW  - Estradiol valerate
KW  -rainbow trout
KW  -gonadal sex differentiation
AB  - This study investigated the effects of administering Estradiol Valerate (E<SUB>2</SUB>V) on gonadal sex differentiation  in  rainbow  trout  (<I>Oncorhynchus  mykiss</I>,  W., 1792). Rainbow trout fry of average weight 0.32±0.02 g, 65 days post fertilization (dpf), which had just started to feed were supplied with a feed containing E<SUB>2</SUB>V  at  a  rate  of 20 mg kg<SUP>-1</SUP> for 8 weeks (65-121 dpf). Fish samples were taken at random  at 156 days (dpf,), 170, 191, 226 and 261 days and changes in fish gonads were analyzed histologically. At 156 dpf of the experiment, it was observed that oocyte formation had started in the fish gonads, suggesting feminization by the administration of the estradiol valerate. Intersex fish were observed at 170 dpf, while oocytes had gathered heads in gonads and sex transformation of some individuals had started at 191 dpf. Oocytes occupied the large areas of gonads and spermatogonia disappeared at 226 dpf as at 261 dpf. At the end of the experiment, sex compositions were 97% female, 3% intersex in the E<SUB>2</SUB>V administration group and 51% female, 49%  female  in  the control group. There were no apparent differences between control group fish and hormone-treated fish as regards oocyte size.
ER  -