盐度、pH、氨氮对钝缀锦蛤稚贝生长及存活的影响

Effect of salinity,pH and ammonia nitrogen on growth and survival to juvenile Tapes conspersus

为探究钝缀锦蛤(Tapes conspersus)稚贝对盐度、pH、氨氮的适应性,本研究在室内可控条件下,分析了不同盐度(10、15、20、25、30、35、40)、pH(2.5、3.0、3.5、4.0、4.5、5.0、5.5、6.0、6.5、7.0、7.5、8.0、8.5、9.0、9.5、10.0)、氨氮(0.5、1、5、10、20、50、100、250 mg/L)对钝缀锦蛤稚贝的生长和存活的影响。不同盐度条件下实验结果表明,钝缀锦蛤稚贝的最适生长和生存盐度为25~35。不同pH条件下实验结果表明,钝缀锦蛤稚贝生存的适宜pH为4.0~8.5,稚贝对低pH耐受性比高pH更强。不同氨氮条件下实验结果表明,氨氮浓度在0.5~10.0 mg/L范围内,稚贝的存活率均为100%;氨氮浓度大于20.0 mg/L时,随着氨氮浓度的升高,稚贝存活率显著下降;在24 h内,不同氨氮浓度下各组稚贝均存活良好,存活率均大于98.33%;48 h、72 h和96 h时,稚贝的半致死浓度分别为123.68、77.36、49.00 mg/L,安全浓度分别为12.37、7.74、4.90 mg/L。

In order to explore the adaptability of juvenile Tapes conspersus to salinity,pH and ammonia nitrogen,this study analyzed effects of different salinity(10,15,20,25,30,35,40),pH(2.5,3.0,3.5,4.0,4.5,5.0,5.5,6.0,6.5,7.0,7.5,8.0,8.5,9.0,9.5,10.0),and ammonia nitrogen(0.5,1,5,10,20,50,100,250 mg/L)on the growth and survival of T.conspersus.The results showed that the optimum salinity for the growth and survival of T.conspersus was 25~35;the suitable pH for survival of the juveniles was 4.0~8.5,and the juvenile shellfish exhibited a higher tolerance to low pH than to high pH;the survival rate of juveniles was 100%when the concentration of ammonia nitrogen was in the range of 0.5~10.0 mg/L.When the concentration of ammonia nitrogen was higher than 20.0 mg/L,the survival rate of juvenile shellfish decreased significantly with the increase of ammonia nitrogen concentration.Within 24 hours,the juveniles of all groups survived well under different concentrations of ammonia nitrogen,and the survival rate was more than 98.33%.At 48 h,72 h and 96 h,the LC_(50) of juveniles were 123.68 mg/L,77.36 mg/L and 49.00 mg/L,respectively,and the safe concentrations were 12.37 mg/L,7.74 mg/L and 4.90 mg/L,respectively.