The Effects Of Periodic Starvation On Nitrogen And Phosphorus Budgets Of Litopenaeus Vannamei And Environmental N&P Loading

Starvation experiments of Litopenaeus vannamei were carried out under laboratory conditions. The time of completely compensatory growth, feeding, faecal production, excretion, growth and exuviation of the shrimp were measured, and the nitrogen and phosphorus budgets of the shrimp were modeled. The effects of periodic starvation on nitrogen and phosphorus budgets of Litopenaeus vannamei and environmental N&P loading were discussed in this paper.In the sarvation-refeeding experiment, the shrimps which had been deprived of food for 1d, 2d and 3d need 3d, 5d and 9d respectively for completely compensatory growth and crude protein contentment. In the starvation period, the N and P excretion rate of the sarvated shrimps decreased with a maximum value at 7:00. In the refeeding period, the N and P excretion rate of shrimps maximized at 19:00 and minimized at 7:00 everyday.In the periodic starvation experiment, group S₁ (starvating 1d every 4d), S₂ (starvating 2d every 7d), S3 (starvating 3d every 12d) and conctrol group S₀ (feeding everyday) of Litopenaeus vannamei were set. The feeding amount of group S₁, S₂, S₃ were 81.15%, 77.19% and 78.80% of that of group S₀, respectively; and the amount of faecal production of group S₁, S₂, S₃ were 64.86%, 59.08% and 56.52% of that of group So, respectively. The final dry weight, the specific growth rate, the amount of crude protein and crude lipid of shrimps had no significant differences in all groups, but the food conversion efficiency of group S₁, S₂, S₃ were higher than that of group So.The nitrogen and phosphorus budgets of the shrimp were depicted as follows:...