作　　者： ; ; ; ; ; ;

机构地区： 汕头大学

出　　处： 《中国水产科学》 2015年第5期950-959,共10页

摘　　要： 为探讨黄斑蓝子鱼(Siganus canaliculatus)长链多不饱和脂肪酸(long-chain polyunsaturated fatty acids,LC-PUFA)合成代谢与渗透压调节的关系,本研究以鱼油(FO)和混合植物油(苏子油与双低菜籽油,VO)为脂肪源配制两种等氮等脂饲料,投喂饲养在3种盐度(10、20和32)下的黄斑蓝子鱼幼鱼8周后,分析了各处理组幼鱼的生长性能和鳃的磷脂脂肪酸组成、Na+/K+-ATPase(NKA)活力及其基因表达。结果显示,相同盐度下,VO组和FO组鱼的生长性能差异不显著(P>0.05);FO组鱼鳃磷脂中的n-3 LC-PUFA含量显著高于VO组(P<0.05),但VO组鱼的n-6 LC-PUFA水平显著高于FO组(P<0.05);VO组鱼鳃的NKA酶活力及其m RNA表达量都显著高于FO组(P<0.05)。不同盐度下,无论VO组还是FO组的鱼,盐度10组鱼的生长性能显著低于盐度20和32组(P<0.05),而其鳃的LC-PUFA含量、NKA酶活力及其m RNA表达量都显著高于盐度20和32组(P<0.05),各指标在后两个盐度组之间差异不显著(P>0.05)。由此可见,盐度10对黄斑蓝子鱼具有一定的胁迫性,导致其生长性能较差。摄食鱼油脂肪源饲料,可以提高鱼鳃磷脂的n-3 LC-PUFA水平;而摄食植物脂肪源饲料时,鱼体可能通过自身合成的n-6LC-PUFA调控鳃的NKA基因表达及其酶活力以调节渗透压。 To explore the relationship between osmoregulation and long-chain polyunsaturated fatty acid （LC-PUFA） biosynthesis in rabbitfish （Siganus canaliculatus）, an 8-week feeding trial was performed in juvenile rabbitfish with diets that contained fish oil （FO） or a blend of vegetable oils （VO;perilla and canola oils） at three salinities：10, 20, and 32. The growth performance, fatty acid composition of gill phospholipids, and activity and expression levels of gill Na＋/K＋ATPase （NKA） under different treatments were analyzed. The results showed that, at the same salinity, there was no effect of dietary lipid source on growth performance （P〉0.05）, whereas n-3 LC-PUFA content in gill phospholipids in the FO dietary groups was significantly higher than those in VO treat-ments （P〈0.05）. In particular, although the contents of n-6 LC-PUFA in VO-fed fish were lower than in FO-fed fish, the opposite was observed for n-6 LC-PUFA contents. Furthermore, the activity and mRNA expression levels of gill NKA in VO groups were significantly higher than those in FO groups （P〈0.05）. Under different salinities, the growth indexes at a salinity of 10 were significantly lower than those at salinities of 20 and 32 in both dietary groups （P〈0.05）, whereas the LC-PUFA contents, and activity and mRNA expression levels of NKA in fish fed VO were significantly higher than that in fish fed VO （P〈0.05）. In addition, there were no significant differences in either of the higher two salinities treatments （P〉0.05）. The results indicate that a salinity of 10 may not suitable for rabbitfish culture. Furthermore, FO-derived diets can improve n-3 LC-PUFA content in gill phospholipids, which helps maintain membrane lipid fluidity and osmotic balance. Alternatively, VO-derived diets can regulate osmotic pressure by synthesizing n-6 LC-PUFA to up-regulate NKA expression and activity.

关 键 词： 黄斑蓝子鱼 盐度 脂肪源 渗透压调节 合成代谢

领　　域： [农业科学] [农业科学]