为探讨饲料中添加不饱和脂肪酸对刀鲚（Coilia nasus）幼鱼脂肪代谢酶活性和肌肉成分的影响，以初始体质量为（2.78±0.09） g的3 000尾刀鲚幼鱼为研究对象，将其随机分为2组（每组3个重复，每个重复500尾），分别投喂不添加和添加4.76%鱼油（不饱和脂肪酸添加源）的配合饲料（实测粗脂肪水平分别为7.86%和11.32%），进行为期60 d的饲养试验。结果表明：2组刀鲚幼鱼的末均质量、末体长、体长/体高、体长/体厚、肝体指数（HSI）及脏体指数（VSI）均没有显著差异（P>0.05），但添加组刀鲚幼鱼的肥满度（CF）显著高于未添加组（P<0.05）。与未添加组相比，添加组刀鲚幼鱼肌肉中粗蛋白质含量显著降低（P<0.05），粗脂肪含量有升高趋势（P>0.05）。2组刀鲚幼鱼肝脏中脂肪酶（LPS）和总脂酶（TLP）活性及脂质过氧化物（LPO）含量均差异不显著（P>0.05）。肝脏中，添加组刀鲚幼鱼肉碱软脂酰基转移酶-Ⅰ（CPT-Ⅰ）和肉碱软脂酰基转移酶-Ⅱ（CPT-Ⅱ）活性显著低于未添加组（P<0.05），而乙酰辅酶A羧化酶（ACC）活性则高于未添加组（P>0.05）；肌肉中，2组刀鲚幼鱼CPT-Ⅰ、CPT-Ⅱ以及ACC活性均无显著差异（P>0.05）。此外，饲料添加4.76%的鱼油后，肌肉中饱和脂肪酸（SFA）和单不饱和脂肪酸（MUFA）含量显著下降（P<0.05），多不饱和脂肪酸（PUFA）、二十碳五烯酸（EPA）+二十二碳六烯酸（DHA）以及n-3 PUFA含量显著上升（P<0.05）。由此得出，提高饲料中不饱和脂肪酸含量可有效地增加刀鲚幼鱼鱼体必需脂肪酸含量，有利于改善鱼体的营养品质，但有升高鱼体内LPO含量的趋势。

In order to evaluate the effects of unsaturated fatty acids (UFA) on lipid metabolism enzyme activities and muscle components of juvenile Coilia nasus, a total of 3 000 juvenile Coilia nasus with an initial body weight of (2.78±0.09) g were randomly divided into two groups (three replicates per group and 500 fish per replicate), and the fish in the two groups were fed two formulated diets contained different levels of lipid. One diets contained 4.76% fish oil (additive source of UFA) and the other diet did not contain fish oil (the measured levels of crude lipid were 11.32% and 7.86%, respectively). Then the fish from two groups were fed the two diets for 60 days. The results showed that there were no significant differences between two groups in the final average body weight, final body length, body length/body height, body length/body thickness, hepatosomatic index (HSI) and viserosomatic index (VSI) (P>0.05), while the condition factor (CF) in adding group was significantly higher than that in non-adding group (P<0.05). Compared with non-adding group, the muscle crude protein content in adding group was significantly decreased (P<0.05), while the muscle ether extract content showed an increasing trend (P>0.05). Furthermore, there were no significant differences between two groups in the activities of lipase (LPS) and total lipoidase (TLP) and lipid peroxidation (LPO) content in liver (P>0.05). In liver, the activities of carnitine palmityl transferase-Ⅰ (CPT-Ⅰ) and carnitine palmityl transferase-Ⅱ (CPT-Ⅱ) in adding group were significantly lower than those in non-adding group (P<0.05), while the acetyl-CoA carboxylase (ACC) activity was significantly higher than that in non-adding group (P<0.05). In muscle, the activities of CPT-Ⅰ, CPT-Ⅱ and ACC were not significantly different between two groups (P>0.05). In addition, the contents of saturated fatty acids (SFA) and monounsaturated fatty acids (MUFA) in muscle were significantly decreased and the contents of polyunsaturated fatty acids (PUFA), eicosapntemacnioc acid (EPA), docosahexaenoic acid (DHA) and n-3 PUFA in muscle were significantly increased after added 4.76% fish oil into the diet (P<0.05). In conclusion, improving UFA content in diets can effectively increase the content of essential fatty acid of juvenile Coilia nasus, which is conductive to improve nutrition value of fish, but has a trend to increase the LPO content of fish.