饲料中添加不同脂肪源对半滑舌鳎亲鱼繁殖性能和仔鱼质量的影响

Effect of different lipid source in diet on the reproductive performance and larval quality of tongue sole Cynoglossus semilaevis

以精制鱼油、大豆油、橄榄油为脂肪源配制3组实验饲料,以一种商业饲料为对照组,进行连续56d饲喂半滑舌鳎亲鱼试验,研究不同脂肪源对半滑舌鳎亲鱼繁殖性能、卵子脂肪酸组成和仔鱼质量的影响。结果显示,对照组亲鱼的相对产卵量最高,橄榄油组次之,鱼油组比橄榄油组低,豆油组最低。对照组的卵子畸形率最低为9.77%,鱼油组为14.53%,橄榄油组为19.4%,豆油组最高为35.17%(P<0.05)。同时对照组与鱼油组仔鱼畸形率分别为3.34%和3.12%,橄榄油组为8.85%,豆油组为17.35%(P<0.05)。对照组的孵化率也最高,为95.49%,鱼油组次之,为84.88%,橄榄油组为79.57%,豆油组最低,为74.27%(P<0.05)。表明半滑舌鳎亲鱼的产卵期、卵子发育以及仔鱼的成长期都需要饲料中维持一定量n-3HUFA,特别是二十二碳六烯酸(DHA)。油酸和亚油酸(LA)在半滑舌鳎卵子的发育过程被选择性保留下来,起着重要的作用。推断出用单一的植物油或者动物油作为脂肪源都不能很好地为其提供必需脂肪酸。

Three experimental diets with fish oil, soybean oil and olive oil as different lipid source and a commercial diet as control were used to feed broodstock of tongue sole Cynoglossus semilaevis for 8 weeks to investigate the effects of different fat source on spawning performante, fatty acids composition in eggs and quality of larvae. Results showed that in terms of the relative fecundity, the control was the highest, followed by olive oil treatment, fish oil treatment, and soybean oil treatment as the lowest. The abnormal egg ratio of control was the lowest follwed by, fish oil treatment, olive oil treatment, and soybean oil treatment as the highest （9.77%, 14.53%, 19.4% and 17.35% respectively） （P〈0. 05）. Abnormal larva ratio among treatments was significantly different （P〈0.05） （3.34%, 3.12%, 8.85% and 17.35% respectively）. Hatching rate of control was the highest, followed by fish oil treatment, olive oil treatment, and soybean oil treatment as the lowest （P〈0.05） （95.49%, 84.88%, 79.57% and 74.27 % respectively）. It indicated that during spawning period, a certain amount of n-3 HUFA in diet, especially docosahexenoic acid （DHA） needs to maintain egg development and larval growth. Oleic acid and linoleic acid （LA） were selectively retained and played an important roles in tongue sole egg development process. We conclude that soybean oil or olive oil or fish oil as a single lipid source of diets can not provide sufficient fatty acids for tongue sole C. semilaevis.