Investigation of participating different proportions of the 17ß-estradiol and 17A-methyltestosterone hormones on the ahli cichlid (Sciaenochromis ahli Trewavas, 1935)

This study was performed in order to investigate the effects of 17ß-estradiol (17ß-ES) and 17-methyltestosterone (17?-MT) hormone use on the growth, development, survival, sex ratio and color change of the ahli cichlid (Sciaenochromis ahli Trewavas, 1935).In this study, no hormone was added to the control feed, while six other feeds were prepared by adding 20, 40, 60 mg/kg 17ß-ES and 20, 40, 60 mg/kg 17?-MT hormone to each, resulting in seven different types of feed for the study. The Ahli cichlid, mean weight was determined as 0.42±0.04 g, were stored such that there replications for each group. The fish were fed with the feeds for a period of 4 months.At the end of the study, the highest weight gain was observed in the 60 mg/kg 17?-MT group (2.62±0.11 g), and the difference with groups fed with 17ß-ES was found to be statistically significant. Similar statistical differences were also identified with regards to the specific growth rate, the relative growth rate, and feed conversation. When the sex change rates were evaluated, it was determined that all fish in the 17-MT hormone groups were male, while the rates of feminization for the 17ß-ES hormone groups were 91.11%, 88.88% and 93.33%, respectively. Survival rates were determined as 80%, 95.56%, 84.44%, 93.33%, 77.78%, 84.44% and 84.44%, respectively, with the best survival ratebeing observed in the 20 mg/kg 17ß-ES group (95.56%). When the results of the physical color analysis were evaluated, it was determined that the best coloration was achieved in the 17-MT groups, and that the difference with the groups was statistically significant (P<0.05). Accordingly, the L* values varied between 32.98±4.44 and 61.35±2.19, the a* values between -7.06±0.22 and -3.42±0.11, and the b* values between -7.74±0.10 and 11.65±0.03, while the Chroma (C*) and Hue (Habº) angle values varied between 7.54±0.22 and 13.60±0.01, and between 119.76±0.05 and 239.73±4.86, respectively.At the end of the study, the 17-MT hormone was determined to have a greater effect than the 17ß-ES hormone on the growth, feed evaluation rate, sex change and pigmentation of ahli cichlids.Key Words: Ahli cichlid, 17ß-estradiol, 17?-methyltestosterone, growth, sex change, pigmentation