Spawning and season affect lipid content and fatty acid composition of ovary and liver in Japanese catfish (Silurus asotus)

The influences of spawning and season on lipid content, lipid classes, and fatty acid composition were assessed in ovary and liver of wild and culture d Japanese catfish (Silurus asotus). The lipid content (7.3 +/- 1.6 g/100 g wet wt.) of ovary from wild catfish at spawning was higher than that at po st-spawn, However, no influence of spawning on the lipid content of liver w as observed. Docosahexaenoic acid [DHA, C22:6(n-3)] in ovary lipids was 12. 3 +/- 0.5% of total fatty acids. The percentage of n-7 monounsaturated fatt y acids in triacylglycerol from the ovary and liver in the spawning season was high. Percentages of C22:6(n-3) in phosphatidylcholine and phosphatidyl ethanulamine from ovary were higher during spawning than after spawning, No significant differences were observed in the lipid content of ovary and li ver from cultured catfish between seasons (summer vs, winter), Content of a rachidonic acid (C20:4n-6) in ovary and liver from cultured catfish was hig her in summer than in winter, There were differences in lipid classes of ov ary and liver by spawning and season, These results suggest that the lipid metabolism in Japanese catfish is greatly influenced by spawning and season . (C) 2001 Elsevier Science Inc. All rights reserved.