Effects of β-ecdysone and polypodine-B on moulting and growth of prawn, Penaeus orientalis

Effects of the mixture of β-ecdysone and polypodine-B (2:1 W/W) on the moulting and growth of prawn, Penaeus orientalis were studied in laboratory by rearing the animal with the added compound diets. The results showed that the addition of the moulting hormone (M. H) mixture to compound diets, from 1.33×10^-6 to 30×10^-6, could increase moulting activity and growth rate of the prawn to different extents, among which the 5. 33×10^-6-10.67×10^-6 addition had statistically significant effects. However, 60×10^-6 added diets caused moulting and growth inhibitions and cuticle thickening. The analyses of protein, water and ash contents of the prawn showed no remarkable differences between hormone dosed animals and the control.