INFLUENCE OF N-3 HIGHLY UNSATURATED FATTY-ACID DEFICIENCY ON THE LIPID-COMPOSITION OF BROODSTOCK GILTHEAD SEABREAM (SPARUS-AURATA L.) AND ON EGG QUALITY

A feeding experiment was conducted on gilthead seabream (Sparus aurata ) broodstock to investigate the incidence of n-3 highly unsaturated fa tty acids (n-3 HUFA) dietary deficiencies on the lipid composition of female liver, gonads and eggs, in relation to spawning quality. Broods tock were fed a control (C) diet or a n-3 HUFA deficient (D) but linol enic acid rich diet. After 20 weeks of feeding, the results showed tha t levels of total neutral (TNL) and total polar (TPL) lipids of female gonads and eggs were independent of diet. However the fatty acid comp osition of phosphatidylcholine (PC), pho sphatidylethanolamine (PE) an d phosphatidylinositol (PI) of female liver, gonads and eggs in the tw o groups of fish showed marked differences, reflecting the influence o f fatty acid levels in the broodstock diets. This influence was even h igher in TNL than in the phospholipid classes examined. In fish fed n- 3 HUFA deficient diet, fatty acid composition of TNL of female gonads and eggs reflected the diet more than liver. A higher egg production i n broodstock fed C diet (1.8% n-3 HUFA in diet) was extended to spawni ng quality such as percentages of fertilised and hatched eggs.