Seasonal Changes in Fatty Acid Composition of Cod Liver, Flesh, Roe, and Milt Lipids

• Published in: Journal of the Fisheries Research Board of Canada
• Main Authors: Jangaard, P. M., Ackman, R. G., Sipos, J. C.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1967
• Subjects: General Medicine; Gadus morhua
• Online Access: http://dx.doi.org/10.1139/f67-053; http://www.nrcresearchpress.com/doi/pdf/10.1139/f67-053

The fatty acid compositions of lipids from an isolated population of inshore cod (Gadus morhua L.) caught near Terence Bay, Nova Scotia, were determined each month on pooled samples of representative fish. Cod liver oil was studied over a period of 17 months, cod flesh for 12 months with the fatty acid compositions of milt, roe, flesh, and liver lipids being determined from some large, individual fish.The fatty acids of flesh lipids were independent of sex and showed very little, if any, seasonal changes except a slight variation in the long-chain monounsaturated acid 20:1 (max 2.8% vs. avg 1.6% and 1.1%). This was especially evident in large fish where the maximum (3.7%) coincided with the period of best "condition," August to November. There was also a significant difference between large and medium size fish in that in very large fish the content of 22:6 was much lower (26% vs. 33%). Liver oils in female fish contained increasing amounts of 20:1 (4.5 to 14.9%) and 22:1 (1.8 to 12.3%) fatty acids with increased fat content of the liver, maxima occurring in late summer and fall. In the male fish this seasonal trend was not as obvious. No other acids showed any definite seasonal variation. In the fatty acids of roe and milt lipid no definite relationship could be established between ripening and fatty acid composition. The fatty acids of the milt were similar to the roe except for a higher percentage of 18:1 and lower percentage of 16:1. The unsaponifiable matter was higher in milt than in roe lipids.These results indicate that due to the large variations that can occur in the fatty acid content of lipids from individual fish, a single analysis could give a fatty acid composition quite different from the average of a large number of determinations.