CHANGES OF FATTY ACID COMPONENTS AND CONTENT OF COILIA NASUS IN THE YANGTZE RIVER DURING SPAWNING MIGRATION

In order to elucidate the changes in the components and contents of fatty acid of female Coilia nasus in the Yangtze River during spawning migration process, the components and contents of various fatty acid in the hepatopancreas, muscle and ovary of Coilia nasus were determined from three aspects of migration distance, ovarian development and body length. The results showed that 28 kinds of fatty acids were detected in the three tissues of 62 female Coilia nasus, including 8 saturated fatty acids (SFA), 6 monounsaturated fatty acids (MUFA) and 14 polyunsaturated fatty acids (PUFA). Among all the fatty acids, MUFA were the most abundant, accounting for more than 56.23% of the total fatty acids in each tissue. Specific fatty acids with higher levels included C18﹕1, C16﹕0, C16﹕1, DHA and EPA. During migration, the total amount of fatty acids in the hepatopancreas of Coilia nasus increased from (526.61±38.50) mg/g in Chongming to (587.21±124.72) mg/g in Anqing, but decreased by 33.03% and 57.09% in muscle and ovary respectively. The total amount of fatty acids, SFA, MUFA and PUFA in muscle were positively correlated with body length (P<0.05), but the contents of total fatty acids and fatty acids components in hepatopancreas and ovary had no significant correlation with body length (P>0.05). During the ovarian development from stages Ⅱ to Ⅳ, the contents of total fatty acids in hepatopancreas and muscle decreased by 47.56% and 22.40%, respectively, but increased from 364.17 to 418.95 mg/g in ovary. The contents of C18﹕1, EPA and C16﹕1 in hepatopancreas and muscle decreased, but increased by 1.21, 1.36 and 1.31 times in ovary (stages Ⅱ to Ⅲ), respectively, indicating that these fatty acids were also significantly transferred during ovarian development. The present study also found that there were more fatty acids in muscle of large size Coilia nasus, the abundance of SFA and MUFA in each tissue, and EPA and DHA in the ovaries, which provided sufficient nutrition for migration activities and gonad development.