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

The effect of feeding four semi-purified diets containing different li pid sources (anchovy oil, linseed oil, com oil and pork lard) on fecun dity, egg hatchability and egg and spent gonadal tissue fatty acid com position 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 hatch ability. 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 conta ining anchovy oil, both fecundity and egg hatchability were significan tly improved (P<0.01). Eggs from broodstock fed anchovy oil as sole di etary lipid had a higher n-3 highly unsaturated fatty acid (HUFA) cont ent (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 t hat each of these n-3 HUFAs may play different and specific roles in c rustacean reproduction and that either or both must be included in the broodstock diet.