Effects of Lanthanum-Amino Acid Complexes on Egg Hatching and Nauplius Metamorphosis of Penaeus chinensis

Studies have been carried out on the effect of lanthanum-amino acid complexes on embryo development and nauplius growth ofPenaeus chinensis. The experimental results indicate that: (1)The optimum concentrations of lanthanum-proline and Lanthanumphenylalanine for the development of eggs in monocell and dicell stages are 1.50～ 4.00mg/L and 0.50～3.00 mg/L, respectively, the egg hatching rates being raised by 21.0 ～ 46.0% and 23.0 ～42.8% ( P ＜ 0.05 ) respectively. (2)The optimum concentrations of lanthanum- proline complex and Lanthanum-phenylalanine complex for the growth ofnauplii are 1.50～4.00 mg/L and 0.50～3.00 mg/L, the metamorphosis rate from nauplius to protozoea being raised by 16.4 ～27.5% and 20.4～26.7% (P ＜ 0.05 ) respectively. (3)The positive effect of lanthanum-amino acid complexes on egg hatching and nauplius metamorphosis of Penaeus chinensis is better than that of lanthanum. With regard to the positive effect, lanthanum-proline complex is better than Lanthanum-phenylalanine complex.