盐度对日本鳗鲡生长及非特异性免疫酶活性的影响

Effects of salinity on growth and nonspecific immune enzyme activities of Anguilla japonica

利用实验生态学和酶学方法,在浙江省海洋水产养殖研究所清江试验场研究了盐度对平均体长为25.1±5.6cm的日本鳗鲡(Anguilla japonica)生长及其血清溶菌酶(LZM)、超氧化物歧化酶(SOD)及碱性磷酸酶(AKP)活性的影响,实验持续60d.实验设置了5个盐度梯度(盐度5、10、15、20、25)和对照组(盐度0),每梯度设3个平行组,各组盐度和pH值保持一致.日本鳗鲡血清中免疫酶活力指标:碱性磷酸酶、溶菌酶、超氧化物歧化酶在实验的第7天和第14天测定.实验结果表明,盐度5组相对增重率最高(279.78%±28.37%),其次是盐度10组(278.74%±22.25%),盐度15、20、25组相对增重率分别为234.39%±21.28%、230.28%±26.31%、228.01%±29.29%,对照组相对增重率为233.20%±25.18%,盐度5和10组与对照组差异显著(p<0.05),其余各组与对照组差异不显著.第7天和第14天,盐度10组碱性磷酸酶活性最高,分别为225.05 U/dm3和251.11 U/dm3,其次是盐度5组,分别为221.76 U/dm3和236.01 U/dm3,显著高于对照组(p<0.05).第7天和第14天盐度20、25组溶菌酶活性显著高于对照组(p<0.01).超氧化物歧化酶随着盐度的升高呈逐步上升趋势.第14天,盐度20、25组溶菌酶活性仍保持较高水平,SOD回落至对照组水平,而各组AKP较第7天略有上升.

Effects of different salinities on growth, activities of serum lysozyme （LZM）, superoxide dismutase （SOD） and alkaline phosphatase （AKP） in Anguilla japonica, in mean body length of 25.1 ＋ 5.6cm ,were studied by experimental ecological and enzyme analysis methods at Qingjiang station of the Zhejiang Maricuhure Research Institute for 2 months. This study set up 5 experimental treats （ salinity 5, 10, 15, 20, 25 ） and a control group （ salinity 0）, each gradient had 3 parallel treats, with a same temperature and pH. The immune index, such as ly- sozyme, superoxide dismutase and alkaline phosphatase in serum of Anguilla japonica were respectively measured on days 7 and 14. The results showed that the highest relative weight growth rate （279.78% ＋28.37% ） was ob- tained at salinity 5, then at salinity 10 （278.74% ＋ 22.25 ）. The relative weight growth rate at salinity 15, 20 and 25 were 234.39% -＋ 21.28% ,230.28% ＋ 26.31% ,228.01% ＋ 29.29%, respectively. The relative weight growth rate of the control group was 233.20% ＋25.18%. The treatments of salinity 5 and the salinity 10 were sig- nificantly higher than that of control group （p 〈 0.05 ）. The other treatments showed no significant difference （p 〉 0.05）. The highest AKP activity on days 7 and 14 were obtained at salinities 10（225.05 U/dm3, 251. ll U/dm3）, then at salinities 5 （221.76 U/dm3 , 236.01 U/dm3）. The two treatments had significant difference than the control （p 〈0.05 ）. On days 7 and 14, the LZM activity was higher at salinities 20 and 25 than that of the con- trol groups （p 〈 0.05）, The SOD activity increased with raising salinity. On day 14, LZM kept at higher level at salinities 20 and 25 and SOD activities dropped to the level in control group, and AKP activity increased.