野生与人工养殖牙鲆亲鱼不同组织脂肪酸的比较

为研究脂肪酸对牙鲆繁育性能的影响, 采用生物化学方法, 对野生和养殖牙鲆亲鱼肌肉、肝脏及卵中脂肪酸组成分别进行测定。结果表明: (1) 牙鲆肌肉、肝脏和卵中脂肪含量大小关系为肝脏>卵>肌肉。野生亲鱼肌肉和卵中脂肪含量显著低于养殖亲鱼(P<0.05), 肝脏脂肪含量与养殖亲鱼无显著差异; (2) 牙鲆亲鱼3种组织中均检测出21种脂肪酸。野生亲鱼肌肉中饱和脂肪酸(SFA)与养殖亲鱼无显著差异, 单不饱和脂肪酸(MUFA)显著低于养殖亲鱼(P<0.05)。肝脏和卵中SFA显著高于养殖亲鱼(P<0.05), MUFA与养殖亲鱼无显著差异; (3) 野生亲鱼肌肉、肝脏和卵中高不饱和脂肪酸(PUFA)的含量, 尤其是肝脏和卵中C20:5n-3(EPA)、C22:6n-3(DHA)的含量均显著低于养殖亲鱼(P<0.05), 但肌肉和卵中的C20:4n-6(ARA)含量明显高于养殖亲鱼(P<0.05); (4) 野生牙鲆亲鱼肌肉、肝脏和卵中n-3/n-6 PUFA及EPA/ARA显著低于养殖亲鱼(P<0.05), 肝脏中DHA/EPA显著高于养殖亲鱼(P<0.05), 但野生亲鱼肌肉和卵中的DHA/EPA与养殖亲鱼无显著差异。比较结果说明, DHA、EPA和ARA等PUFA是与牙鲆繁殖性能密切相关的重要脂肪酸。在牙鲆亲鱼养殖过程中, 除了提供牙鲆亲鱼足够的脂肪酸营养外, 也应注意各种脂肪酸, 尤其是PUFA中各种脂肪酸之间的添加比例, 从而保证亲鱼的繁殖性能及卵和仔鱼的质量。

A comparative study on fatty acid composition in different tissues of the wild and cultured Paralichthys olivaceus broodstocks

Lipid contents and fatty acid composition in muscle, liver and egg of the wild and cultured Paralichthys olivaceus broodstocks were determined by biochemical methods, to ascertain their effects on the reproductive performance. The results indicated that lipid contents in muscle, liver and egg of both wild and cultured broodstocks were as follows: liver > egg > muscle. The lipid contents in muscle and egg of wild broodstocks were significantly lower than those of cultured (P<0.05), while there were no differences of lipid content in liver between the wild and cultured; 21 fatty acids were detected in muscle, liver and egg. There were no differences of SFA in muscle between the wild and cultured (P>0.05), but MUFA was significantly lower than that of cultured (P<0.05). SFA in liver and egg of wild broodstocks was significantly higher than that of cultured (P<0.05), but there were no differences of MUFA in liver and egg between wild and cultured (P>0.05); The PUFA, especially EPA and DHA in muscle, liver and egg of wild were significantly lower than those of cultured (P<0.05), but ARA of wild was significantly higher (P<0.05); The ratio of n-3/n-6 PUFA and EPA/ARA in muscle, liver and egg of wild were significantly lower than those of cultured (P<0.05), the ratio of DHA/EPA in liver of wild was significantly higher (P<0.05), while there were no differences of the ratio of DHA/EPA in muscle between wild and cultured (P>0.05). Results of this study indicated that, PUFA, especially DHA, EPA and ARA, could be conjectured to be essential to P. olivaceus during sexual maturation. Thus, in order to ensure the reproductive performance and quality of egg and fry, an adequate supply of fatty acids was needed, meanwhile, the proportion of several fatty acids, especially PUFA, also needed to be considered.