EFFECT OF N-3 HUFA LEVEL IN BROODSTOCK DIETS ON EGG QUALITY OF GILTHEAD SEA BREAM (SPARUS-AURATA L)

A variety of morphological, biological and biochemical parameters of freshly spawned eggs of gilthead seabream (Sparus aurata L.,) were studied to determine the optimum n-3 HUFA level in broodstock diets necessary to obtain a high-quality spawn, The effect of very high dietary n-3 HUFA levels on fish reproduction was also investigated. Broodstock were separated into 8 groups and fed four diets containing different levels of n-3 HUFA, ranging from 1.13 to 3.15%, for 3 months. Spawning and egg qualities were evaluated daily by 7 parameters, Besides, 8 samples of eggs were taken during the experimental period and were analyzed for proximate and fatty acid composition, After 3 weeks of feeding, significantly improved spawning quality in the broodstock fed 1.6% n-3 HUFA was observed in terms of fecundity, hatching and larval survival, Unfertilized egg rates were significantly reduced by the increase in dietary 20:5n-3. The highest level of dietary n-3 HUFA was associated with a decreased fecundity and yolk sac hypertrophy in just hatched out larvae. n-3 HUFA content in the eggs showed a positive correlation with dietary n-3 HUFA, mainly due to the change in 20:5n-3 content of the eggs.