Studies Of The Interaction Effect Of Temperature And Salinity On Growth And Metabolism For Litopenaeus Vannamei

Respiration and excretion are the basic physiological activity of energy metabolism for animal, physiological state of animal and culture environment are reflected through them. Knowing and mastering the respiration and excretion of shrimps will be a new guidance for rational stocking and water quality management.In order to provide the basis for health aquatic breeding, Taking white pacific adult shrimp (Litopenaeus vannamei) as the research object, the characteristics of growth and metabolism in different water culture environment are studied in this paper. The interaction effect of water temperature and salinity on oxygen consumption rates, ammonia-nitrogen excretion rates and phosphate excretion rates for white pacific shrimp (Litopenaeus vannamei) were studied in high, middle, and low concentrations of nutrient background value. And the interaction effect of water temperature and salinity on growth rates, feeding rates and food conversion efficiency are preliminarily studied. As well as all experiment data are used to nonlinear regression analysis. The main findings are as follows:(1) Based on two-factor orthogonal experiment in three concentrations of nutrient background value, the oxygen consumption rates increase with the increasing of temperature, and its decrease with the decreasing of salinity. The interaction of is obviously. at the same time, the oxygen consumption rates in the high concentrations of nutrient background value is slightly less than in the low concentrations of nutrient background value.(2) In three concentrations of nutrient background value, the nonlinear regression equation of oxygen consumption rates for Litopenaeus vannamei are respectivelyR_O1=0.06S^0.066e^0.065T ( R² =0.9919, P＜0.01 ) , R_o2=0.163S^0.071e^0.163T( R²=0.905477,P＜0.01 ), R_o3 =0.1768S^0.064e^0.181T ( R² =0.966469,P＜0.01 ) .Because of these regression equations, the oxygen consumption rates of Litopenaeus vannamei are simulated in different water temperature, salinity and water condition to convenient for determined the oxygen supply rate in the process of industrialized culture.(3) Based on two-factor orthogonal experiment in three concentrations of nutrient background value, phosphate excretion rates decrease with the increasing of temperature, and its decrease with the decreasing of salinity. And phosphate excretion rates in high temperature changed slightly with the decreasing of salinity. It is show that, in the low temperature, the effect of salinity on phosphate excretion rates is more obvious than high temperature. In addition, the demand of phosphate for food is increase with the decreasing of salinity.(4) The value of O/N is increase with the increasing of temperature, and its decrease with the decreasing of salinity. It is show that, in the condition of high temperature and salinity, the fat energy expenditure is higher than the condition of low temperature and salinity. In three concentrations of nutrient background value, The value of O/N is about 24.(5) In three concentrations of nutrient background value, the nonlinear regression equation of phosphate excretion rates for Litopenaeus vannamei are respectivelyR_p1=0.830671S^0.367e^-0.036T ( R² =0.966,P＜0.01 ) , R_p2 =0.723345S^0.328e^-0.0243T( R² = 0.9004,P＜0.01), R_p3=0.305261S^0.568e^-0.030T ( R² =0.969,P＜0.01). And the nonlinear regression equation of ammonia-nitrogen excretion rates for Litopenaeus vannamei are respectively R_N1 =1.025S^-0.166e^0.049T , ( R² =0.986,P＜0.01 )R_N2=3.7915S^-0.351e^0.017T , ( R² =0.9256,P＜0.01 ) R_N3 =1.0647S^-0.0184e^0.0028T ,( R² = 0.8076, P＜0.01). Because of these regression equations, the ammonia-nitrogenor phosphate excretion rates of Litopenaeus vannamei are simulated in different water temperature and salinity to convenient for evaluating the culture level and culture model, as well as controlling the culture water and collecting volume of food.(6) In the interaction effect of temperature and salinity, the nonlinear regressionequation of growth rate for Litopenaeus vannamei is R_F=0.323696S^0.055e^0.34T ( R² = 0.966043,P＜0.01) , so the optimum growth conditions is simulated. And the nonlinear regression equation of feeding rate is R_G = 0.02467S^0.102e^0.474T( R² = 0.94003,P＜0.01) to convenient for controlling the collecting volume of food. So water pollution due to excess food is avoided. In addition, the nonlinear regression equation of food conversion efficiency is E_F =0.460S^0.087e^0.544T( R² =0.953245,P＜0.01 ) to convenient for increasing feed efficiency, reducing production cost and reducing water environment pollution due to shrimps stools.