COMPARATIVE STUDY OF THE EFFECTS OF HUFA IN DRY DIETS AND NATURAL FOODS ON FECUNDITY AND EGG DIAMETER OF FEMALE BROODSTOCK OF WHITE LEG SHRIMP (LITOPENAEUS VANNAMEL)

During 2 months (from April to June, 2008) we studied the suitable quantity of Highly Unsaturated Fatty Acids (HUFA) for desirable fecundity and egg diameter of female broodstock of white leg shrimp (Litopenaeus vannamei). Similar dry food containing Isonitrogeneous material (31. 5% protein) and Isolipid (6. 9% lipid) was used but with different levels of HUFA (1, 2 and 3%). Also, the HUFA of natural foods (Perinereis worm, melalis bivalvia and cuttlefish) was analyzed. We compared the effects of four levels of dietary HUFA (1, 2 & 3 % HUFA of dry diets and the average HUFA of natural diets) on fecundity and egg diameter of female broodstock of white leg shrimp. The fecundity and egg diameter of natural diet and HUFA 3% were not significantly different (P>0. 05). The fecundity of natural diet and HUFA 3% was significantly higher than the other two treatments (P<0. 05) and also the egg diameter of HUFA 3% and natural diet was significantly higher than the other two treatments (P<0. 05). According to the results of fecundity and egg diameter measurements, both natural and HUFA 3% diets are suggested as suitable for white leg shrimp breeding.