维生素C对龙睛金鱼亲鱼繁殖性能、免疫及后代仔鱼质量的影响

Effects of dietary vitamin C on reproduction performance and offspring larval quality of goldfish Carassius auratus

为研究饲料中添加维生素C(vitamin C,VC)对龙睛金鱼Carassius auratus亲鱼繁殖性能的影响,在基础饲料中分别添加不同比例的L-抗坏血酸-2-磷酸酯(作为VC添加剂),制成VC含量分别为0.175(对照)、0.875、1.75、3.50 mg/g的4种试验饲料,分别饲喂4组体质量为(6.60±0.12)g/尾的龙睛金鱼亲鱼,雌鱼、雄鱼放养比例为1∶2,饲喂3个月后进行人工育苗。结果表明:饲料中添加VC能显著增加龙睛金鱼雌性亲鱼的相对怀卵量和雄性亲鱼的精子密度(P<0.05);饲料中添加1.75 mg/g VC能显著提高受精卵的发眼率、出膜率和仔鱼4 d的成活率(P<0.05);饲料中添加VC能显著提升亲鱼血清中非特异免疫因子补体C3水平,增加亲鱼血清、卵巢与精巢的抗氧化性能(P<0.05)。研究表明,本试验条件下,饲料中添加0.875~1.75 mg/g的VC对龙睛金鱼亲鱼的繁殖性能具有积极促进作用,可促进性腺分泌,提高精卵的数量和质量,并进一步改善后代仔鱼质量。

Ten female and twenty male broodstock goldfish Carassius auratus with body weight of(6.60±0.12)g(♀1∶♂2)were reared in a 1.5 m×1.5 m×0.6 m tank,fed diets containing 0.175(control group),0.875,1.75 and 3.50 mg/g L-ascorbate-2-phosphate(vitamin C,VC)at water temperature of 20℃for 3 months,and then artificial reproduction was conducted to investigate the effects of VC on reproduction performance and offspring quality.The results showed that the absolute fecundity of female goldfish and the sperm concentration of male goldfish were significantly affected by the dietary level of VC(P<0.05),significant increase in the eyed rate,hatching rate and survival rate of 4-day old larvae in the broodstock fish fed the diet with supplementation of 1.75 mg/g VC(P<0.05).There were significantly higher non-specific immune factors including complement C3 levels in serum and antioxidant capacity in ovary and testis of brood stock fed the diet with supplementation of VC(P<0.05).In conclusion,the high dose(0.875 to 1.75 mg/g)VC supplementation in the diet leads to improve the reproductive performance of goldfish broodstocks,inluding gonad secretion,quantity and quality of sperm and eggs,and offspring quality under the experimental conditions.