Seasonal changes in fatty acid composition of cod liver, flesh, roe, and milt lipids.

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 i...