Analytical Method for Nutirtional Condition of Marine Fish Larvae by Individual

建立了一种灵敏、简便的海水鱼苗脂肪酸分析方法，以测定鱼苗中二十二碳六烯酸(DHA)和二十碳五烯酸(EPA)的含量作为其营养状况的指标。用该新方法分析了野生海鱼仔鱼个体的脂肪酸含量和组成。1.将脂肪酸9-安替基甲酯的高效液相色谱引入新方法。对酯的高灵敏荧光检测使得能够分析一个人的一只眼睛和身体部分。2.分析的一些过程被修改，以减少耗时的复杂操作。脂肪提取后的所有过程都可以在一个一次性玻璃瓶中进行。在3.5h内完成分析，一天可分析10个样品。3.对在日本丰嘉湾和木须湾捕获的326尾(18种)野生鱼幼体的体细胞部分进行了脂肪酸分析。在所有个体中，显著的脂肪酸只有5种，即DHA(18-32%)、棕榈酸(18-27%)、环氧丙烷(4-19%)、十八碳烯酸(7-12%)和硬脂酸(4-23%)。4.按体长分类的每9个个体的DHA含量(μg/个体)。2.4-3.1 mm和4.4-5.2 mm棕色比目鱼(CV 0.6-1.0)和4.8-6.0 mm日本凤尾鱼(CV 0.7-0.9)的变异系数较高。太平洋檀香的变异系数普遍较低(0.2-0.5，只有一种例外为0.9)。在野生海鱼仔鱼发育的特定阶段，海水鱼仔鱼所需的DHA含量变化很大。

A sensitive and convenient procedure for fatty acid analysis of marine fish larvae has been developed in order to determine docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) contents as an indicator of their nutritional condition. Fatty acid content and composition in each individual of the wild marine fish larvae have been analyzed by the new procedure.1.High-performance liquid chromatography (HPLC) of fatty acid 9-anthrylmethyl esters was introduced to the new procedure. Highly sensitive fluorescent detection of the esters enabled the analysis of one eye and somatic part from one individual.2.Some processes of the analysis were modified to reduce time-consuming complicated operations. All processes after lipid extraction could be carried out in a single disposable glass vial. The analysis was completed within 3.5 hours, and about ten samples could be analyzed in one day.3.Somatic part of the 326 individuals of wild fish larvae (18 species) caught in the Funka and Mutsu Bays, Japan, were subjected to the fatty acid analysis. In all individuals, remarkable fatty acids were only five components, DHA (18-32 %), palmitic acid (18-27 %), EPA (4-19 %), octadecenoic acid (7-12 %) and stearic acid (4-23 %).4.DHA contents of the somatic part (μg/individual) were summarized for every nine individuals classified by body lengths. Coefficient of variance (CV) was high in the 2.4-3.1 and 4.4-5.2 mm brown sole (CV 0.6-1.0) and 4.8-6.0 mm Japanese anchovy (CV 0.7-0.9). Pacific sandlance showed generally lower CV (0.2-0.5 with one exception 0.9). The contents of DHA essential for marine fish larvae widely vary at specific stages during development of wild marine fish larvae.