Effects Of Aeromonas Hydrophila And Environment Factors On Immune-related Indexes Of Procambarus Clarkii

This study was conducted on Procambarus clarkii to study the effects of environmental stress, such as heavy metal (Cu2+,Zn2+,Cd2+),NH4+-N,NO2--N,Aeromonas hydrophila, on THCs,PO,SOD,antibacterial activity,lysozyme activity,Na+-K+-ATPase and bacteria amount in the haemolymph. The results showed that:After injection of 1.5×104 cfu/ml,1.5×106 cfu/mL A.hydrophila, Immune indexes of both GroupⅠandⅡshowed significant changes. THCs and SOD of both groups decreased first and increased later with injection time; In GroupⅠ, A.hydrophila injection increased PO,antibacterial activity,lysozyme activity,Na+-K+-ATPase, and showed a decreasing trend after the first rise during 1～96 h; In GroupⅡ, the above indexes were inhibited significantly first, and recoveried gradually after 96 h.After immersion stress of Cu2+(3 mg/L,10mg/L,20 mg/L,40 mg/L),Cd2+(1 mg/L,5 mg/L,15 mg/L,30 mg/L) and Zn2+(5 mg/L,15 mg/L,30 mg/L,60 mg/L), immune indexes of all trial groups showed significant changes. After immersion 1-96 h, THCs,SOD,PO,antibacterial activity,lysozyme activity of two lower concentration groups of Cu2+,Zn2+,Cd2+ increased a little, and recoveried to original value gradually; But the above indexes of two higher concentration groups decreased significantly, and reached the lowest in 96 h; Na+-K+-ATPase of all heavy metal groups was inhibited during 1～96 h, and decreased accordingly within the concentration and time.After immersion stress of NH4+-N (5 mg/L,15 mg/L,30 mg/L,50 mg/L), immune indexes of all trial groups showed significant changes. After immersion 1-96 h, THCs,SOD,PO,antibacterial activity,lysozyme activity,Na+-K+-ATPase of 5 mg/L group increased a little, and recoveried to original value gradually; the above indexes of 15 mg/L,30 mg/L,50 mg/L group were inhibited during 1-96 h, and the above indexes of 15mg/L group recoveried in 96 h, but that of 30 mg/L,50 mg/L group decreased accordingly within the time, reached the lowest in 96 h.After immersion stress of NO233-N (1mg/L,4 mg/L,8 mg/L,10 mg/L), immune indexes of all trial groups showed significant changes. Na+-K+-ATPase of all NO2--N group decreased accordingly within the concentration and time, and reached the lowest in 96 h; After immersion 1-96 h, THCs,SOD,PO,antibacterial activity,lysozyme activity of 1 mg/L group increased a little, but not significantly; the above indexes of 4 mg/L,8 mg/L,10 mg/L group were inhibited significantly accordingly within the concentration and time.Bacteria amount in the haemolymph showed some change during the above environment stress. During 1-96 h, Bacteria in the haemolymph of control and two lower concentration groups didn't exist, or the amounts were few,1-7 cell/100μL haemolymph; Bacteria amount in the haemolymph of two higher concentration groups increased significantly.