牛磺酸对半滑舌鳎（Cynoglossus semilaevis）亲鱼繁殖性能及仔鱼质量的影响

摘要

研究了牛磺酸对半滑舌鳎(Cynoglossus semilaevisGünther)亲鱼繁殖性能、抗氧化功能、卵子及仔鱼质量的影响。在基础饲料中分别添加0、0.5%、1.5%的牛磺酸，配制3组(对照组T-0、T-0.5、T-1.5)等氮等脂的配合饲料，在室内流水养殖系统进行为期63 d的养殖实验。研究结果显示，在饲料中添加0.5%牛磺酸，不仅能够提高半滑舌鳎亲鱼的相对产卵量，还能促进亲鱼体内睾酮和雌二醇的分泌(P<0.05)；T-0.5组浮卵率、受精率、孵化率、卵径、油球直径、3日龄、7日龄仔鱼体长均显著高于对照组(P<0.05)，T-0.5组和T-1.5组仔鱼畸形率显著低于对照组(P<0.05)；3个实验组仔鱼生存活力指数(SAI)无显著性差异(P>0.05)；饲料中添加牛磺酸能够提高其肝脏和性腺中牛磺酸含量，降低肝脏中半胱胺双加氧酶活性；T-0.5组肝脏、血清、精巢、精液中超氧化物歧化酶(SOD)活性显著高于对照组(P<0.05)，性腺和卵子中丙二醛(MDA)含量显著低于对照组(P<0.05)。研究结果表明，饲料中添加牛磺酸能够提高半滑舌鳎亲鱼繁殖性能、抗氧化功能、卵子及仔鱼质量。在本研究条件下，牛磺酸含量为0.5%的饲料组为最佳饲料组。%Tongue soleCynoglossus semilaevishas high economic values and is extensively exploited in northern China. However, there have been few reports on the broodstock nutritional requirements of this species. In this study we investigated the effects of dietary taurine on the reproductive performance, the antioxidant function, and the egg and larval qualities of tongue sole C. semilaevis. Three experimental diets containing different levels of taurine (control T-0, T-0.5 and T-1.5%) were formulated and randomly distributed into three 3 m×2.5 m×1.2 m cement ponds with 15 females and 20 males in each for 9 weeks. Dietary taurine (0.5%) improved the relative fecundity and boosted the secretion of testosterone and estradiol in tongue sole broodstock (P<0.05). Moreover, compared to T-0, the T-0.5 diet significantly elevated the buoyant eggrate, the fertilization rate, the hatching rate, the egg diameter, the oil droplet diameter, and the larval length at 3 DPH and 7 DPH (P<0.05). The broodstock fed with the control (T-0) diet exhibited higher abnormal rate than the other two groups (P<0.05), and there was no significant difference in larval survival activity index (SAI) among the different dietary treatments (P>0.05). The concentrations of taurine in the liver and the gonad were increased and the activity of cysteamine dioxygenase was decreased along with the increase in dietary taurine. Compared to the control group, the activity of superoxide dismutase (SOD) in the liver, the serum, the testis, and the semen was also significantly higher in broodstock fed with T-0.5 diet (P<0.05), and the level of malondialdehyde (MDA) in the gonad and the eggs were significantly lower (P<0.05). In conclusion, these results suggested that dietary taurine may have considerable effects on the reproductive performance, the antioxidant function, and the egg and larval quality of C. semilaevis, and that the optimal concentration of taurine in the diet should be 0.5%.