Feeding effect of cholesterol in the diet on sex hormones concentrations and the gonads' growth of yearling common carp (Cyprinus carpio)

Backgrounds:there are some evidences that cholesterol can affect fish reproductive system. objectives: in this study the effect of high diet cholesterol on fish sex hormones and gonads weight was investigated. methods: a randomized experiment was conducted on 90 immature common carp. the fishes were divided into three groups with three replicates each (control, 0.5% cholesterol diet, and 1% cholesterol diet). after one-month feeding, progesterone, estrogen and testosterone were measured. results: the level of progesterone in control group, 0.5% cholesterol and 1% cholesterol diet were 1.83±0.42, 2.45±0.38 and 2.62±0.52 ng/ml, respectively. also the level of estrogen in control group, 0.5 % and 1% cholesterol diet were 3670.34±186.26, 3791.20±98.48, and 3836.78±81.74 pg/ml, respectively., while those of testosterone levels were 1.75±0.319, 2.09±0.425, and 2.25±0.321 ng/ml, respectively. the highest and the lowest body weight and gonad weight were observed in fish fed %1 cholesterol and the control, respectively. the results showed positive effects of cholesterol on sexual hormones, the 0.5 % cholesterol diet and the 1% cholesterol diet did not show any significant difference in the sexual hormones levels. conclusions: the results indicated that the effect of cholesterol on the these sex hormones, gonad weight, body length and body weight was significant (p<0.01). we can conclude that diets of 0.5% cholesterol can be used to increase the amount of sexual hormones in common carp