Biochemical composition, lipid classes and fatty acids in the ovary of the shrimp Pleoticus muelleri bate

Abstract

Abstract 1. 1. Seasonal changes in the biochemical composition, lipid classes and fatty acid distribution in the ovary of the shrimp P. muelleri were studied during 1984 and 1985. 2. 2. Neutral lipids were mainly composed by triaclyglycerols, free fatty acids, free and steryl sterols, partial glycerols, pigments, wax esters and hydrocarbons. 3. 3. Polar lipids included mostly phosphatidylcholine, phosphatidylethanolamine, lysoderivatives of choline and ethanolamine, sphingomyelin, pigments and unidentified glycolipids. 4. 4. Major fatty acids were 16:0, 16:1n-7, 18:1n-9, 20:5n-3 and 22:6n-3. The fatty acid composition of neutral lipids varied significantly throughout the year in contrast to that of polar lipids which remained relatively constant. 5. 5. Ovarian maturation during summer involved a simultaneous increase in ovary mass and in protein and lipid concentrations. Fully developed ovaries accumulated polar lipids and tricylglycerols. 6. 6. Palmitic acid (16:0) increased with maturation of the ovary probably as a result of de novo synthesis whereas the levels of 16:1 and 18:1 fatty acids were not significantly changed. 7. 7. After summer spawning the ovary lost large amounts of polar lipids, and in late summer the shrimp intensified feeding, as a result of which neutral lipids accumulated. The ratio of neutral lipids/polar varied from 0.5 in the summer to 2.1 in the autumn. 8. 8. The increase of the polyenoic fatty acids, 20:5n-3 in the spring (ratio 22:6 20:5 = 0.46 ) and 22:6n-3 in the autumn ( 22:6 20:5 = 1.19 ) may be caused by a change in the composition of dietary lipids.