饲料中甲基睾酮含量对阿里雌鱼生长及体色的影响

Effects of Dietary Methyltestosterone on Growth and Body Pigmentation of Female Sciaenochromis fryeri

为探明甲基睾酮对阿里雌鱼生长及体色的影响,在水温22~24℃下,将初始体质量(5.78±1.05)g的阿里雌鱼450尾随机分为5组,每组3个平行,每个平行30尾,饲养于75 cm×60 cm×28 cm水族缸中,分别投喂含甲基睾酮0、4、8、12、16 mg/kg 5个梯度的饲料,观察8周增色时间和4周停药期鱼的生长及体色变化。试验结果显示,不同含量的甲基睾酮对阿里雌鱼的成活率无影响,均为100%;12 mg/kg的甲基睾酮组的体质量显著高于其他各组(P<0.05);12 mg/kg与16 mg/kg甲基睾酮组增色效果差异不显著(P>0.05),但显著高于其他各组(P<0.05);增色后的阿里雌鱼在后4周停药期中,体色呈现先增艳,后又缓慢减弱现象,但仍维持在较艳的程度。表明外源甲基睾酮对阿里雌鱼具有适应性反应,增色后的阿里雌鱼体色能够稳定4周以上,甲基睾酮适宜添加量为12 mg/kg。

In order to study effects of methyltestosterone on growth and body colour in female Sciaenochromis fryeri,450 individuals of female S.fryeri with initial body weight of(5.78±1.05)g were randomly divided into 5 groups and fed diets containing methyltestosterone at a dose of 0(control group),4,8,12,and 16 mg/kg for 8 weeks,and then all fishes were fed the control diet for 4 weeks.Growth performance and body pigmentation of female S.fryeri were determined every 2 weeks during the 12 weeks experimental period.The results showed that there was significantly higher average body weight in the female S.fryeri in 12 mg/kg group than that in the other groups(P<0.05),even though with 100%of average survival rate in each group.There was no significantly difference in body pigmentation between 12 mg/kg group and 16 mg/kg group(P>0.05),significantly higher than that in the other groups(P<0.05).The fish colour was all elevated somewhat in all groups,and then decreased slightly,being remained at stable level constantly after the colouration of female S.fryeri for 8 weeks was enhanced.The findings indicated that the methyltestosterone had adaptive reaction to female S.fryeri,and that the optimal methyltestosterone dose was of 12 mg/kg.