青石斑鱼与卵形鲳鲹卵黄囊仔鱼发育过程中脂肪特性及脂肪酸含量变化

定量研究了青石斑鱼(Epinephelus awoara)和卵形鲳鲹(Trachinotus ovatus)的卵黄囊仔鱼发育过程中脂肪特性及脂肪酸的变化。结果表明:两种仔鱼具有不同的脂肪组成,青石斑鱼卵黄囊仔鱼中性脂与极性脂比值为0.97～1.22;卵形鲳鲹卵黄囊仔鱼中性脂与极性脂比值为1.88～3.21。两种卵黄囊仔鱼的总脂含量均随发育而逐步下降,且都主要消耗中性脂。青石斑鱼卵黄囊仔鱼中性脂内含量高的脂肪酸为:18∶1n-9,16∶0,DHA,16∶1和18∶0;极性脂中含量高的脂肪酸为:DHA,16∶0,18∶0和18∶1n-9。卵形鲳鲹卵黄囊仔鱼中性脂中含量高的脂肪酸为:18∶1n-9,18∶2n-6,DHA,16∶4n-3和16∶0;极性脂中含量高的脂肪酸为:DHA,16∶0,18∶1n-9和18∶2n-6。青石斑鱼卵黄囊仔鱼发育至2日龄时中性脂主要脂肪酸均显著下降;而卵形鲳鲹卵黄囊仔鱼发育至1日龄时中性脂主要脂肪酸均显著下降。两种卵黄囊仔鱼极性脂中的主要脂肪酸均在1日龄时显著升高。上述结果表明尽管脂肪和脂肪酸组成存在显著差异,但青石斑鱼和卵形鲳鲹的卵黄囊仔鱼在发育过程中利用脂类的规律具有相似性。

Changes in lipid characteristics and fatty acid contents of developmental yolk sac larvae of Epinephelus awoara and Trachinotus ovatus

Lipid as well as fatty acid is important substrate fueling normal metabolism and development of marine fish larvae.The changes in lipid characteristics and fatty acid contents of developing yolk-sac larvae of Epinephelus awoara and Trachinotus ovatus were investigated in this study.The newly hatched larvae and 1 d,2 d,3 d post hatching larvae of E.awoara and T.ovatus were sampled and their lipid contents and fatty acid profiles were assayed quantitatively.The results indicated that there were different lipid compositions between the two larvae.The neutral lipid/polar lipid ratio in E.awoara was between 0.97 and 1.22 during the development of yolk-sac larva.While in T.ovatus it was between 1.88 and 3.21.The total lipid contents of the two larvae both decreased with the development due to large consumption of neutral lipid.The dominating fatty acids in neutral lipid of E.awoara yolk-sac larva were 18∶ 1n-9,16∶ 0,DHA,16∶ 1 and 18∶ 0.While DHA,16∶ 0,18∶ 0 and 18∶ 1n-9 were the dominating in polar lipid.However,the dominating fatty acids in neutral lipid of T.ovatus larvae were 18∶ 1n-9,18∶ 2n-6,DHA,16∶ 4n-3 and 16∶ 0,and in polar lipid were DHA,16∶ 0,18∶ 1n-9 and 18∶ 2n-6.Significant decreasing of main fatty acids in neutral lipid appeared at 1 day post hatching in T.ovatus larva and at 2 days post hatching in E.awoara larva respectively.But the contents of main fatty acids in polar lipid increased significantly at 1 day post hatching in both larvae.It is therefore suggested that despite the significant differences in lipid and fatty acid profiles,the lipid consumption law was similar during the development of yolk-sac larvae of E.awoara and T.ovatus.