Effects Of Ammonia-N With Different Concentrations And Different Low PH Values On Immune Functions Of Procambarus Clarkii

This paper studies effect of ammonia-N and pH on immune parameters of Procambarus clarkii, analyzes the changes of different immune parameters under different ammonia levels or pH levels within 48h, and aims to discuss the immunological regulation mechanism of P. clarkii. The results were as follows:1. 4 ammonia-N levels of 0(the control), 25, 50 and 75mg/L were designed using ammonium chloride solution of lOOg/L to adjust. During the experiment, ammonia levels were measured every 4h and varied at 0.16±0.06(the control), 26.12±0.12, 54.36±0.23, 73.20±0.17mg/L, respectively, and no P. clarkii died. For each treatment, there were three triplicate groups. 3 crayfish were sampled randomly from each group at the time intervals of 1h, 2h, 4h, 8h, 12h, 24h and 48h, respectively.The results indicated that ammonia-N had significant effects on 9 immunol parameters except THC (Duncan's multiple range test, P<0.05). During the 48h of exposure to ammonia-N solutions, lysozyme (LSZ), phenoloxidase (PO), superoxide dismutase (SOD) activity in serum and PO activity in hepatopancreas, phagocytic activity and clearance efficiency to Staphyloxaus aureus, the concentration of total protein and the concentration of oxyhemocyanin in serum increased at first and then decreased gradually, especially, PO of serum in treatment groups show much higher activity than that in control group at any sampling time. LSZ, SOD activity in hepatopancreas, LSZ, PO, SOD in muscle and the total hemocyte counts (THC) in ammonia-N groups decreased with time elapsed. Both of acid phophatase (ACP) and alkaline phosphatase (ALP) activity in the 3 tissues had increasing trends. It meant that hign concentration of ammonia-N could promote immune functions of P. clarkii in a short-term (<8h), but long-time stimulations would decrease crayfish's immune ability.2. 4 pH levels of 7.6(the control), 6.0, 4.0 and 2.0 were designed using 1mol/L HCl and 1mol/L NaOH to adjust. During the experiment, pH levels were measured every 4h and varied at 7.62±0.10(the control), 2.31 ± 0.12, 4.23 ± 0.15, 6.47±0.11, respectively, and no P. clarkii died. For each treatment, there were three triplicate groups. 3 crayfish were sampled randomly from each group at the time intervals of lh, 2h, 4h, 8h, 12h, 24h and 48h, respectively.The results indicated that pH values had significant effects on 10 immune parameters (Duncan's multiple range test, P<0.05). During the 48h of exposure to low pH solutions, LSZ, SOD, ACP, ALP activity in serum decreased gradually with the increase of treatment time, and the extent of decrease depended on the levels of pH values. PO...