Effects Of Temperature And Salinity On Physiology And Biochemistry Of Litopenaeus Vannamei And Cyclina Sinesis And Construction Of Energy Budget Model

Litopenaeus vannamei and Cyclina sinesis are important economic aquatic organisms in the world,which not only play an important role in the aquaculture industry,but also have extremely important economic value.The two species have the characteristics of wide temperature and wide salinity.Therefore,the study of the two kinds of organisms is of great significance.In recent years,the breeding of L.vannamei mainly focused on growth,disease resistance and stress resistance.Among them,the selection of improved varieties with fast growth will help to increase the output,reduce the cost and improve the economic benefit of the enterprise.Temperature and salinity will directly affect the growth,development and reproduction of L.vannamei and C.sinesis,and further affect their food intake,metabolism,energy budget,enzyme activity and other physiological and biochemical indexes.Organisms can adapt to the changes of the environment through their own regulation.According to the current research situation at inside and outside the laboratory,and the main problems at present,this paper studied the feeding,metabolism and energy budget of different families of L.vannamei under different temperature and salinity,and the response of short-term salinity stress to the physiology and biochemistry of L.vannamei.The relevant parameters of the dynamic energy budget model of individual growth of L.vannamei and C.sinesis.The main results are as follows:1 The effects of temperature（20℃,25℃,30℃,35℃）and salinity（30,35,40,45）on the growth and energy budget of three families（N310004,N310010,N310011）of L.vannamei were studied.The experimental period was 40 days,and the physiological indexes such as feeding rate,oxygen consumption rate,ammonia excretion rate and defecation rate were measured every 10 days.The individual energy budget of L.vannamei families in different periods(S1（0-10d）,S2（11-20d）,S3（21-30d）,S4（31-40d）was analyzed.The results showed that:（1）The family N310004 grew fastest when the temperature was 30℃and salinity was 30,and the total specific growth rate was 9.79±0.22%.The specific growth rates of S1 and S4 were significantly higher than those of the other two families（p<0.05）.（2）Temperature and salinity have significant effects on family feeding and metabolism.In the temperature experiment:in the range of experimental temperature,the feeding rate and metabolic rate of each family increased with the increase of temperature.At the same temperature,except for S1 period,the feeding rate of N310004 was significantly higher than that of the other two families.In S1 and S2 periods,the oxygen consumption rate of N310011 families was higher than that of N310011 families.In S3 and S4 periods,the oxygen consumption rate of N310010 families was significantly higher than that of N310011families and N310004 families.During the S1-S3 period,the ammonia excretion rate of N10004 families was significantly lower than that of other families,and the fecal excretion rate of N310010 families was significantly higher than that of other families in four periods.In the salinity experiment,except for S1,the feeding rate of N310004was significantly higher than that of the other two families at the same salinity.In S1period,the oxygen consumption rate of N310011 family was significantly higher than that of other families,the oxygen consumption rate of N310010 family was significantly higher than that of other families in S2-S4 period,and the ammonia excretion rate of N310004 family was significantly lower than that of other families in S1-S4 period.（3）In the temperature experiment,the growth energy of the three families was inverted bell with temperature,and the peak value appeared at 30℃.The growth energy and the proportion of growth energy of N310004 families were significantly higher than those of the other two families at 20-35℃.In the salinity experiment,the energy intake of L.vannamei was mainly used for respiratory metabolism,and there was no significant difference in energy intake among the three families during S1 period.N310010 families had significantly higher energy for respiratory metabolism than other families,and N310004 families had significantly higher growth energy than other families in S2-S4 period.It is mainly due to its higher energy intake,lower respiratory energy and lower metabolic energy.2 Effects of salinity stress on oxygen consumption rate,ammonia excretion rate and immune enzyme activity of L.vannameiTaking L.vannamei as the research object,the experiment was set to three kinds of salinity stress S30-40-30,S30-40,S30-25,the salinity of the control group was set to30,and the stress time was 96 h.The oxygen consumption rate,ammonia excretion rate,O/N ratio,superoxide dismutase（SOD）,catalase（CAT）,alkaline phosphatase（AKP）and acid phosphatase（ACP）activities of L.vannamei were measured and analyzed.The results showed that:（1）Salinity stress had a significant effect on the oxygen consumption rate of L.vannamei（p<0.05）.From the beginning of stress,the oxygen consumption rate of L.vannamei was significantly higher than that of the control group.At the same time,the ammonia excretion rate of L.vannamei increased at first and then decreased in each experimental group.The mole ratio of oxygen to nitrogen of L.vannamei in three groups of stress experimental group was more than 24,and the utilization rate of fat and carbohydrate was higher under salinity stress.（2）Salinity stress had significant effects on SOD,CAT,AKP and ACP of L.vannamei.SOD,AKP and ACP mainly act on hepatopancreas,while CAT mainly acts on muscles.The peak activity of SOD and CAT appeared at different time points,showing a trend of rising at first and then decreasing.ACP activity increased at first and then decreased in hepatopancreas,and increased at first and then temperature in muscle,and the enzyme activity at each time point was significantly higher than that in the control group.The activity of AKP increased gradually in hepatopancreas and decreased gradually after 24hours,while it was stable in muscle.3 Determination of basic parameters of dynamic energy budget model of L.vannamei and C.sinesis under different salinityThe results were as follows:（1）Shape coefficientδ_m:the shape coefficientδ_m is obtained from the regression relationship between shell length and soft tissue wet weight,the value is 0.4901.（2）Parameters related to starvation experiment:the 35 day starvation experiment of L.vannamei and the 45 day starvation experiment of C.sinesis were carried out to determine the energy per unit volume per unit time to maintain life[（?）_M],the energy required to form structural matter per unit volume per unit time[E_G],and the maximum storage energy per unit volume per unit time[E_M].The average values of[E_G],[E_M]and[（?）_M]were 1413.05J/cm³,1108.14J/cm³ and 99.74J/（cm³·d）,respectively,and those of[E_G],[E_M]and[E_M]were 1533.18J/cm³,1792.18J/cm³ and10.81J/（cm³·d）,respectively.（3）Parameters related to the feeding experiment of C.sinesis Linnaeus:the feeding parameters of C.sinesis at different salinity（35,45,55）were measured at 25℃,which mainly included the maximum feeding rate per unit surface area per unit time and the maximum absorption rate per unit surface area per unit time.When the salinity was 35,the maximum feeding rate{J_Xm}and maximum absorption rate{P_Xm}were 292.65J/（cm²·d）and 133.93J/（cm²·d）,respectively.When salinity is 45,the maximum ingestion rate and absorptivity{J_Xm}and absorptivity{P_Xm}of C.sinesis Linnaeus are 94.75J/（cm²·d）and 44.18J/（cm²·d）,respectively,and when salinity is 55,they are 36.72J/（cm²·d）and 7.90J/（cm²·d）,respectively.4 Based on the theory of dynamic energy budget（DEB）,the individual growth model of C.sinesis.The results showed that the individual growth model could well simulate the growth of soft body dry weight of C.sinesis Linnaeus in Sang gou Bay sea area.There was a significant linear correlation between the simulated and measured values（R²=0.9872）.