INFLUENCE OF DIETARY-LIPID SOURCES ON FECUNDITY, EGG HATCHABILITY AND FATTY-ACID COMPOSITION OF CHINESE PRAWN (PENAEUS-CHINENSIS) BROODSTOCK

The effect of feeding four semi-purified diets containing different lipid sources (anchovy oil, linseed oil, com oil and pork lard) on fecundity, egg hatchability and egg and spent gonadal tissue fatty acid composition of Chinese prawn (Penaeus chinensis) broodstock was compared with a fresh clam diet in a 60-day feeding trial. Broodstock prawn fed the diet containing pork lard showed poor fecundity and low egg hatchability. Broodstock fed the diets containing linseed or com oil showed improved egg production (P<0.05); however, no significant improvement in hatchability was observed. When broodstock were fed the diet containing anchovy oil, both fecundity and egg hatchability were significantly improved (P<0.01). Eggs from broodstock fed anchovy oil as sole dietary lipid had a higher n-3 highly unsaturated fatty acid (HUFA) content (27.6%) compared with those of prawn fed diets containing linseed oil (19.5%), corn oil (14.0%) or pork lard (12.8%). Good correlations between the 20:5n-3 content of the egg lipid and fecundity and between 22:6n-3 content and hatchability were observed. The results suggest that each of these n-3 HUFAs may play different and specific roles in crustacean reproduction and that either or both must be included in the broodstock diet.