南美白对虾卵和无节幼体脂肪酸组成及其与饵料的关系

Fatty acid profiles in egg and nauplius of Penaeus vannamei and the relationship with maturation diets

为探讨南美白对虾 (Penaeusvannamei)在幼体发育过程中对多不饱和脂肪酸的需求及饵料对卵、无节幼体脂肪酸组成的影响 ,对南美白对虾卵和无节幼体脂肪酸的组成进行测定和分析 ,并比较幼体阶段主要脂肪酸含量及其变化。在卵脂肪中占主要比例的脂肪酸为棕榈酸、棕榈油酸、亚油酸、花生四烯酸和DHA ,而在无节幼体中则为棕榈酸、棕榈油酸、亚油酸、花生四烯酸、EPA和DHA。在从卵到无节幼体的发育过程中 ,除EPA和DHA占总脂肪酸比例有较明显的上升外 ,其他脂肪酸所占比例均有不同程度的变化 ,总体变化特点为饱和脂肪酸的比例逐渐下降 ,而多不饱和脂肪酸的比例上升。亲虾饵料沙蚕 (Nereisspp .)的脂肪酸组成分析表明 ,沙蚕与卵及无节幼体脂肪酸的组成具有一定的相关性。

The eggs and nauplius of Penaeus vannamei were collected in middle April and Nereis spp. was used as the maturation diets. The analysis results show that the major fatty acids in the eggs are C16∶0, C16∶1n 7,C18∶2n 6,C20∶4n 6 and C22∶6n 3, and in the nauplius are C16∶0,C16∶1n 7,C18∶2n 6,C20∶4n 6,C20∶5n 3(EPA), and C22∶6n 3(DHA). During the early development stages from egg to nauplius, the ratios of EPA and DHA to total fatty acids increase obviously, but the ratios of the other fatty acids change slightly. The trend is that the ratio of total satuated fatty acids to total fatty acids declines gradually, and that of polyunsaturated fatty acids increases gradually from egg to nauplius. At the same time, the content of n 3 polyunsaturated fatty acids increases, but the content of n 6 polyunsaturated fatty acids declines. In the blood worm Nereis spp, the fatty acid profiles are C16∶0(28.59%), C16∶1n 7 (18.58%),Trans C18∶2n 6(4.95%), C20∶4n 6 (13.53%) , EPA(3.38%) and DHA (8.56%). The results implicate that the fatty acid profiles in blood sand worm have more influence on those in egg than those in nauplius.