| The effect of fishing, temporary rearing and transport in wild fingerlings of Eleutheronemarhadinumwas studied in this paper,aiming to provide a theoretical basis for breeding and vivotransport. According to the changes in indicators of survival, growth, feeding and antioxidantenzymes of liver in different salinity seawater, better understand the adaptability and diseaseresistance of Eleutheronema rhadinum in different salinity, exploringits optimum growth salinity,providing a theoretical basis to carry out the salinity acclimation and aquaculture development ofEleutheronema rhadinum.1. The fishing, temporary rearing and transport in wild fingerlings of Eleutheronemarhadinum.We carry out some technical tests of juvenile Eleutheronema rhadinum in Xingken water area inQidong City, Jiangsu province and the water area around chongming island, Shanghai from Julyto October in2011. It contains fishing, temporary rearing, and transport. According to the twonetting gear, we get6122Eleutheronema rhadinum with inserting network, and1130Eleutheronema rhadinum with trawlnet. The survival rate is87.9±2.0%and78.4±2.4%. Thesurvival rate of the former is higher than the latter. We temporary rear600Eleutheronemarhadinum in cement pit indoor with52.7%rate of survival, while we provisionally rearing2574in cement pool outdoor with25.3%survival rate. The weight gain rate and specific growth rateof former is slightly higher, but there was no significant difference. We use water box to shorthaul, the average survival rate is higher than above90%with the density of90~120, and above85%with the density of150. There is no significant difference between the survival rate of twomethods of transportation within4h, but the difference is obvious when it is more than4h. Theyare92±7.9~94±5.0%，and49.0±4.2~64.5±4.9%. Among the study of this long-distance transport(2~8h), the survival rate is inversely proportional with time by using water box, but there is nosignificant difference by using oxygenation fry bag. The survival rate is92.0±7.9%inanesthetized group in8h transport, and0in the group without anesthetic.2. The influence of survival, growth and feeding of Eleutheronema rhadinum in differentsalinity. The effects of salinity on survival, growth, and feeding of Eleutheronema rhadinum in salinity30,salinity24, salinity18, salinity12, salinity6, and the freshwater were studied. Eleutheronemarhadinum, average body weight5.19±0.48g, were held in1000L black plastic circular cylinderfor56days for each group. The results showed that, the survival rate of freshwater group wasonly46%, while the remaining five groups are both higher than80%. With the increasing ofsalinity, the growth rate of Eleutheronema rhadinumrose first and then fell, and the highest pointpresents in salinity12. Otherwise, the phenomenon of water drinking of the juvenile fish isobvious in salinity30and salinity24. The weight, truncus weight, weight gain rate (WGR),truncus weight gain rate (TWGR), special growth rate (SGR) and condition factor in salinity12and salinity6were all significantly higher than other salinity groups (P<0.05). There were nosignificantly difference in weight and truncus weight among the group of salinity30, salinity24,salinity18and freshwater (P>0.05). The weight gain rate (WGR), truncus weight gain rate(TWGR), special growth rate (SGR) and condition factor in freshwater were all significantlylower than other salinity groups (P<0.05). There were no significantly changes in body length ineach salinity groups (P>0.05). With the increase of salinity, the feeding rate was rose first andthen fell on the whole. The feeding rate in salinity18, salinity12and salinity6weresignificantly higher than those in salinity30, salinity24and the freshwater (P<0.05). The resultsshow that, juvenile Eleutheronema rhadinum could be survival and citations in the salinity6to30, and salinity12and salinity6were more conducive to grow for juvenile Eleutheronemarhadinum.3. The influence of gill Na~+/K~+-ATPase and liver antioxidant enzymes of juvenileEleutheronema rhadinum in different salinity.We set salinity30,24,18,12,6and freshwater for this study, the average weight of juvenileEleutheronema rhadinum is5.19±0.48g. In this study, the activity of gill Na~+/K~+-ATPase andliver superoxide dismutase (SOD), catalase (CAT) and malondialdehyde (MDA) of liver wareresearched. Results showed that, the activity of gill Na~+/K~+-ATPase in each group have nosignificant difference among7d、28d and56d (P>0.05). With the decreasing of salinity, theactivity of gill Na~+/K~+-ATPase ware significantly increased at7d (P<0.05), but declined andstabilized after28days in salinity18、12and6(P>0.05). In freshwater, the activity of gillNa~+/K~+-ATPase also stabilized after28days (P>0.05), but higher than other salinity groupssignificantly (P<0.05). Results of liver antioxidant enzyme showed that, in salinity30and24,the activity of CAT have no significant difference among three times (P>0.05). With thedecreasing of salinity, the activity of SOD and CAT ware significantly increased at7d in salinity 18,12and6（P<0.05）, and declined to stabilize after28d, have no significant difference withthat in56d（P>0.05）. The activity of SOD and CAT showed the tendency of continue to rise withtime in freshwater (P<0.05). There was no significant difference in the content of MDA in bothsalinity30and24with time（P>0.05）. The content of MDA decreased with decreasing salinityexcept freshwater, and the content of MDA at7d was the highest among three times in allsalinity groups, then declined to stabilize after28d（P>0.05）. The results showed that juvenileEleutheronema rhadinum could endure low salinity, and could be breed in salinity0~30. |
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