| The effect of behavior,viscera in the low salinity seawater and the effect of survival,growth on the juvebile Eleutheronema rhadinum was studied in this paper,aiming to provide a scientific basis for the large scale cultivation and desalting cultivation.According to survival, feeding, growth and antioxidant enzymes in liver and gill Na+/K+-ATPase of juvebile Eleutheronema rhadinum,,which were acclimated to desalination using the different methods.We learn the adaptation of juvebile Eleutheronema rhadinum to the different desalting culture,It will help to choose the optimal method of desalting culture of juvebile Eleutheronema rhadinum,provide theoretical foundation for its breeding and technical support for desalting cultivationThe influence of salinity on,behavior,viscera and survival of juvebile Eleutheronema rhadinum in salinity28,salinity21.salinity14,salinity7,salinity3and30juvebile Eleutheronema rhadinum,everyone of them weigh6.32±0.56g on average,were farmed in It blue circular tank for4d.Results showed:juvebile Eleutheronema rhadinum,farming in freshwater,began dying within lhour and all of them died in4hours. The survival rate of juvebile Eleutheronema rhadinum,farming in the other group,is100%.As salinity decrease,the behavior of juvebile Eleutheronema rhadinum have begun to take on new features.In low-salt (salinity less than3) environmentjuvebile Eleutheronema rhadinum decreased appetite,showed odd behavior and leaded to the death.For example:Swimming of juvebile Eleutheronema rhadinum,which is farmed in low-salt groups, will likely be significantly slower than the others farmed in other salinity groups, juvebile Eleutheronema rhadinum,farming in the freshwater,were not sensitive to physical stimulation.The bait was swallowed and spit out repeatedly by juvebile Eleutheronema rhadinum,and the range of gill cover had greater changed.juvebile Eleutheronema rhadinurnfarming in the freshwater,stopped food and felled scale Under dissection it was observed that the colors of gill start with reddish brown and gradually shade to gray at the end,The colors of liver start with tan and gradually shade to reddish brown at the end.and pathological injure in kidney are obvious.The similar pattern has not been seen for other salinity groups.juvebile Eleutheronema rhadinum,,farming in the other groups,changed behavior within the first2hours of experiment,and returned to normal in the rest time of experimentjuvebile Eleutheronema rhadinum (6.39±0.56g) were acclimated to low-salinity using three different methods,including reducing salinity suddenly(RS), reducing salinity termly(RT), reducing salinity gradually(RG).Results showed:In the process of desalting cultivation during28days,the survival rate is100%in RS,except the freshwater group.juvebile Eleutheronema rhadinum,farming in the freshwater,died within1day.The survival rate is18.7%in RG and5.55%in RT. In28-day feeding experiments,which is after desalting cultivation during28days,the rest of survival juvebile Eleutheronema rhadinum in RG and in RT died within10days.In the process, juvebile Eleutheronema rhadinum stopped food and became "Big Head Fish" in RG and RT.After the entry trial ends,the result showed that:the effects of salinity on feeding rate(FR) of juvebile Eleutheronema rhadinum in salinity28,salinity14,salinity7and salinity3were similar.The effects of salinity on specific growth rate(SGR),growth efficiency(GE)and food conversion efficiency(FCE) of juvebile Eleutheronema rhadinum in salinity28,salinity14,salinity7and salinity3were different.With the increase of salinity, the SGR and GR of juvebile Eleutheronema rhadinum presented earlier increase and later decrease trend.The GE and SGR of juvebile Eleutheronema rhadinum,farming in salinity14group are better than in the other groups.Otherwise,The SGR of juvebile Eleutheronema rhadinum,farming in salinity3group are worse than in the salinity14,salinity28groups.With the increase of salinity, the FCE of juvebile Eleutheronema rhadinum presented earlier decrease and later increase trend.The FCR of juvebile Eleutheronema rhadinum,farming in salinity3group are better than in the other groups.Result showed:the desalting cultivation of juvebile Eleutheronema rhadinum, farming in the salinity14by RS,is better than in the other methods. juvebile Eleutheronema rhadinum (6.39±0.56g) were acclimated to low-salinity using three different methods including reducing salinity suddenly(RS), reducing salinity termly(RT) reducing salinity gradually(RG).The samples were taken regularly to determine Total antioxidant capacity (T-AOC),Superoxide dismutase (SOD),malondialdehyde (MDA) in liver and Na+/K+-ATPase (NKA)in gill after successive1,4,7,14,21and28days respectively.We knew the juvebile Eleutheronema rhadinum acclimated to low-salinity through inquired into their activity and content change rule in this study.In addition to salinity14,MDA content of juvebile Eleutheronema rhadinum,farming in the other group increased and then decreased with time lasted, but decreased at last during the desalting cultivation by reducing salinity suddenly(RS).MDA content of juvebile Eleutheronema rhadinum, farming in salinity14, decreased and then increased with time lasted.but increased at last during the desalting cultivation by RS.The activity of SOD of juvebile Eleutheronema rhadinum increased and then decreased with time lasted.but decreased at last during the desalting cultivation by RS.The activity of T-AOC of juvebile Eleutheronema rhadinum decreased first then increased and decreased with time lasted.but increased at last during the desalting cultivation by RS.The activity of SOD and T-AOC declined with Salinity variation increased under the whole process.The activity of NKA of juvebile Eleutheronema rhadinum increased and then decreased with time lasted.but decreased at last during the desalting cultivation by RS.MDA content of juvebile Eleutheronema rhadinum decreased first then increased and decreased with time lasted and salinity decreased.but increased at last during the desalting cultivation by reducing salinity termly(RT).The activity of SOD of juvebile Eleutheronema rhadinum increased first,decreased second and then decreased and increased with time lasted.but decreased at last during the desalting cultivation by RT.The activity of T-AOC of juvebile Eleutheronema rhadinum increased and then decreased with time lasted and salinity decreased. But decreased at last during the desalting cultivation by RT. The activity of NKA of juvebile Eleutheronema rhadinum increased and then decreased with time lasted and salinity decreased.but decreased at last during the desalting cultivation by RT. MDA content of juvebile Eleutheronema rhadinum decreased first then increased and decreased with time lasted and salinity decreased.but increased at last during the desalting cultivation by reducing salinity gradually(RG).The activity of SOD of juvebile Eleutheronema rhadinum decreased and then increased with time lasted.but increased at last during the desalting cultivation by RG. The activity of T-AOC of juvebile Eleutheronema rhadinum increased and then decreased with time lasted and salinity decreased. But decreased at last during the desalting cultivation by RG. The activity of NKA of juvebile Eleutheronema rhadinum decreased first increased second and then decreased and increased with time lasted and salinity decreased.but decreased at last during the desalting cultivation by RG... |
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