Establishment Of The Closed Colony Laboratory Animal Of Exopalaemon Carinicauda And Its Growth And Reproductive Performance Analysis

Exopalaemon carinicauda is a crustacean with a member of advantages,such as small in shape,rapid growth,short reproductive cycle and strong adaptability to the environment.Therefore,E.carinicauda is more adaptable to breed in the laboratory than other crustacean species.Most of the closed group animals in China are mammals and a few fishes,and there are few studies on the crustacean experimentalization.In this study,the wild population of E.carinicauda was used to construct a closed colony in laboratory conditions.During the process of colony formation of E.carinicauda,the growth and reproduction characteristics,genetic diversity,and serum biochemical indexes were monitored to determine whether the establishment of the closed group is successful.Moreover,it also provides informations on growth,reproduction,genetics,and serum biochemistry for the closed group,adding a new laboratory animal to crustaceans.The main contents of the study are as follows:1.Establishment method of the closed colony of E.carinicauda.The ridge tail white shrimp used in this laboratory was derived from Rizhao Haichen company of Shandong province.The established closed group of E.carinicauda was named Y: YSFR.The breeding method of on-demand mating was used to avoid inbreeding as much as possible.To standardize the environment management and feeding management of E.carinicauda,is not only to promote the standardization of laboratory animals,but also can provide reference to the cultivation methods of crustaceans.2.Analysis of growth and reproductive performance in the process of the closed colony of E.carinicauda establishment.The growth performance of each generation was monitored during the process of construction of the closed colony of E.carinicauda.The weight and other indicators were measured at the age of 60,80,100 and 120.The results showed that the F2 generation has a higher initial weight than the F3-F5 generation,the F3-F5 has a higher instantaneous growth rate than the F2 generation.The relationship between the weight indices of each generation was F2>F5>F4>F3.The relationship between body length indicators is F4>F5>F2>F3.According to a comprehensive analysis,all growth indicators of various generations fluctuate within a certain range,but there is no tendency to increase or decrease,indicating that the growth traits of the closed colony are well maintained.The reproductive performance of each generation during the formation of closed colony of the E.carinicauda was monitored.The body weight of the broodstock,the hatching rate of the fertilized eggs during the breeding period and the survival rate of the zoea were measured.The results showed that the hatching number of the F2-F4 fertilized eggs increased with the increase of body weight.The number of hatching increased with the increase of the number of generations under the same body weight.There is no significant difference(P > 0.05)of the survival rate between the fleas larvae in the F2-F5 generations.The results showed that the reproductive performance of the closed colony was more stable in different generations.3.Analysis of genetic diversity during closed colony of E.carinicauda formation.The closed colony of E.carinicauda established in this laboratory uses microsatellite markers for genetic quality monitoring.Among the 42 microsatellite loci,the number of polymorphic sites(PIC > 0.5),moderate(0.5 < PIC <0.25)and low(PIC <0.25)were 24,15 and 2,respectively.The average value of polymorphic information in F1 generation is 0.5448,the average value in F2 generation is 0.5471,the average value in F3 generation is 0.5413,the average value in F4 generation is 0.5006,the average value in F5 generation is 0.5104,and the average value in each generation is 0.5288.The observed heterozygosities of the F1-F5 generation were 0.4501,0.4636,0.4226,0.4166,and 0.4392,respectively,and the range was 0.0333-1.0000.The expected heterozygosity was 0.5874,0.6010,0.5843,0.5504,and 0.5167,respectively,and the range was 0.0655-0.9356.The results showed that the closed colony of E.carinicauda has high genetic diversity in 42 microsatellite loci.4.Analysis of serum biochemical indexes during Closed Colony Formation of E.carinicauda.In this study,11 serum biochemical indicators of the F2-F5 generation were monitored during the closed colony formation of E.carinicauda.The results showed that the activity of aspartate aminotransferase in the F2 generation was significantly higher(P < 0.05)than in the F5 generation,and there was no significant difference in the activity of alanine aminotransferase and alkaline phosphatase between the different generations of the closed colony(P > 0.05);The levels of total cholesterol in the serum,creatinine,urea nitrogen,and total bilirubin were not significantly different among different generations of the closed colony(P > 0.05).Triglycerides and glucose were different between generations,but there was no clear increase or decrease with increasing generations.The albumin and total protein content did not differ significantly between the generations of the closed colony of E.carinicauda(P> 0.05).The contents of alkaline phosphate and urea nitrogen were significantly different in the closed colony generations(P < 0.05).The experimental results showed that the closed colony of E.carinicauda was more stable during the passage,and had better metabolic level and renal function than the wild E.carinicauda.