Ovarian maturation and haemolymphatic vitellogenin concentration of Pacific white shrimp <i>Litopenaeus vannamei</i> (Boone) fed increasing levels of total dietary lipids and HUFA
Two experiments were carried out to determine the quantitative lipid requirements for ovarian maturation of Litopenaeus vannamei (Boone) broodstock. The first experiment tested the effect of total dietary lipid (TDL) levels of 8.1%, 8.8%, 9.8% and 11.2% on the gonadosomatic index (GSI), hepatosomatic index (HSI), survival and body weight. The second experiment tested the effect of total dietary levels of highly unsaturated fatty acids (TDH) 0.6%, 1.3%, 2.0% and 2.7% on the same parameters mentioned above and on the haemolymphatic vitellogenin (vg) concentration. The GSI was higher in females fed 8.1% TDL as compared with those fed 8.8% TDL (P=0.05), and higher in females fed 8.1% and 8.8% TDL than in those fed 9.8% and 11.2% TDL. lncreasing TDH levels led to increasing levels of highly unsaturated fatty acids (HUFA) in the ovaries (r² = 0.999). However, the GSI was not affected by dietary treatments (P > 0.05). The vg concentration was higher in animals receiving 2.0% TDH as compared with those receiving 2.7% TDH. In conclusion, high TDL levels affected ovarian maturation in a negative way, why TDH levels had no pronounced effect on ovarian maturation within the range tested in this study
