Esculentum On Growth,Digestion,Metabolic And Immune Function Of Juvenile Pampus Argenteus

Silver pomfret(Pampus argenteus)distributed in saline water along China's coast from the Yellow Sea to the South China Sea.Silver pomfret is rich in nutrition,and it is the one of the main species in Chinese fishery.Jellyfish is sometimes considered as valueless,although it is an important food source for silver pomfret.Currently,there were extensive researches of silver pomfret and jellyfish respectively focusing on the biology,nutrition,ecology and ethology.Studies on extra feeding jellyfish of silver pomfret under artificial feeding condition were still relatively rare.In this study,we conducted 5 treatments,including a control group with no extra feeding jellyfish and 4 treatments with extra feeding jellyfish(about 10% silver pomfrets weight)every 1(A),3(B),6(C)and 12(D)days,to analyze the changes of growth and the activities of major protein metabolic enzymes(glutamic-pyruvic transaminase(GPT),glutamic-oxalacetic transaminase(GOT)and glutamate dehydrogenase(GDH))and lipid metabolic enzymes(lipoprotein lipase(LPL)and fatty acid synthetase(FAS))on 36 and 60-day respectively.During the experiment,silver pomfrets were fed daily with selfmade gruel diet.The water was maintained at 25-32? and a half volume of water was changed per day.The main results were listed below.After 36 and 60 days of experiment,the weight gain rate(WGR)and specific growth rate(SGR)of high-frequency groups(A and B)were higher than lowfrequency groups(C and D)and control group,and the WGR and SGR of group A and B significantly higher than those of group D(P<0.05)but no significant difference with control group.The GPT and GOD activities in liver of high-frequency groups were higher than those of low-frequency groups and control group,but significant differences were not found in GPT and GOD activities of serum and liver with feeding jellyfish(P>0.05).Comparison with the liver GDH activities of control group and lowfrequency groups,high-frequency groups showed an increased tendency.The LPL activities of group A were significantly higher than the other groups in serum(P<0.05)after 60 days of the experiment.In liver and muscle,there was no significant difference among the LPL activities of each group(P>0.05).At the end of the experiment,the FAS activities of high-frequency groups were significantly higher than those of low-frequency groups in the liver(P<0.05).In the muscle,the FAS activities of 4 treatments with extra feeding jellyfish were significantly higher than control group(P<0.05).The ?-amylase activities of the silver pomfret esophageal sac of the 36-day control group were significantly higher than that of the low-frequency group(groups C and D)(P<0.05).The ?-amylase activities of silver pomfret intestine were significantly lower in the text group than that in the control group at 60 days(P<0.05).60-day esophageal sac ?-amylase significantly higher than the 36 days(P<0.05).At the 36 th day,only group C pepsase activities were significantly different from control group(P<0.05).There was no significant difference in intestinal trypsase activities among the groups(P>0.05).At 60 days,there was no significant difference among the pepsase activities of esophageal sac and intestine(P>0.05).At 60 days,the esophageal sac lipase activities in group A,B and C were significantly lower than that in group D(P < 0.05),lower than the control group but not significant(P>0.05).There was no significant difference in intestinal lipase activities among the groups.The statistical analysis showed that,under this experimental condition,extra feeding jellyfish could increase the growth performance of silver pomfret to some extent,and the activities of protein and lipid metabolism related enzymes showed an increased tendency.The extra feeding jellyfish could not significantly increase the activity of digestive enzymes in the silver pomfret esophageal sac and intestinal.The esophageal sac has chemical digestive function,but the main digestive organ of the silver pomfret is the intestine.Next,we studied the effects of fed jellyfish on their skin and serum immune and stress indicators of silver pomfret.We elect initial weight as(13.40±5.65)g experimenting.The test set control group and the test group fed jellyfish was,at 2 hour(h),6h,12 h,24h,72 h respectively,determination the serum and skin immune-related enzyme activities(Superoxide Dismutase,SOD;Catalase,CAT;Acetylcholinesterase,AChE;Lysozyme,LZM;Immunoglobulin M,IgM;Complement C3,C3).The main results were listed below.After the fed jellyfish,serum and skin SOD activities were significantly enhanced at 2h(P< 0.05).Compare text group and control group,there was no significant difference in CAT activities between two groups at the same time of serum and skin.Two peaks of serum AChE activities in the text group silver pomfret appeared at 2h and 24 h.The difference in AChE activities in the control group has not been significant(P> 0.05).The trend of LZM activities of the feeding group in skin are increasing gradually,it is significantly higher than the initial value after fed jellyfish(P< 0.05).The content of IgM in the skin of the feeding group gradually increased and then fluctuate.There was no significant change in IgM content in the control group(P> 0.05).In feeding group,serum C3 levels decreased first,then increased and then decreased.There was no significant change in C3 content of skin in control group and feeding group all the time(P> 0.05).The statistical analysis showed that,after fed jellyfish,Most of the immune indicators of silver pomfret in serum did not change significantly,The skin's immune indicators show that the silver pomfret will undergo stress response and gradually adapt after fed jellyfish.