中国四种土壤跳虫对重金属汞的响应

Responses of Four Species of Chinese Soil Collembola to Hg

为了研究汞（Hg）对不同种类跳虫的毒性效应,将曲毛裸长（虫兆）（Sinellacurv isefa）、四刺泡角（（虫兆））（Cemtophysella duplicispinosa）、小原等节（（虫兆））（Proisotoma minuta）、茉莉花长角（（虫兆））（Entomobrya sp.）4种中国优势跳虫物种分别暴露于Hg的6个浓度组中进行24 h,72 h-LC50急性毒性实验,利用Bliss法测得其4种跳虫的24 h LC50分别为92.42、36.85、34.93、47.56 mg· L-1,其95％置信区间分另为68.57 ～ 168.6、29.61～43.53、25.57～44.94、34.33～65.11 mg· L-1;72 h的LC50为21.92、20.17、18.44、15.99 mg·L-1,其95％置信区间分别为16.18～ 29.82、6.64～ 29.81、13.87～ 26.45、10.03～ 21.37 mg· L-1.将小原等节（（虫兆））和茉莉花长角（（虫兆））分别暴露于Hg的6个相对较低浓度组中进行28 d生存繁殖实验,得到成虫存活数量和幼虫繁殖及生存数量.结果表明,4种跳虫中茉莉花长角（（虫兆））和曲毛裸长（（虫兆））对汞有较强的耐受性,小原等节（（虫兆））次之,四刺泡角（（虫兆））较弱.此外,小原等节（（虫兆））在Hg2＋浓度为0.05 mg·L-1范围左右条件下有低剂量刺激效应.

To study the toxic effects of Hg on diverse species of Collembola,four Chinese dominant species of collembolans,Sinella curviseta,Ceratophysella duplicispinosa,Proisotoma minuta and Entomobrya sp.were exposed to six different concentrations of Hg for 24 h,72 h LC50 measurement.The LC50 values for S.curviseta,C.duplicispinosa,P.minuta and Entomobrya sp.were calculated according to the Bliss method to be 92.42,36.85,34.93,and 47.56 mg· L-1,and 95％ confidence limits were 68.57 ～ 168.6,29.61 ～ 43.53,25.57 ～ 44.94 and 3433 ～65.11 mg·L-1,respectively,while the corresponding 72 h-LC50 values were 21.92,20.17,18.44,and 1599 mg L-1,and 95％ confidence limits were 16.18 ～29.82,6.64 ～29.81,13.87 ～26.45 and 10.03 ～2137 mg-L-1.At the same time,the Proisotoma minuta and Entomobrya sp.were exposed to Hg of six different lower concentrations for 28 d survival and reproduction experiment to determine the numbers of adults and offspring.The result shows that Entomobrya sp.and S.curviseta have higher tolerance for Hg,followed with P.minuta,while C.duplicispinosa ranks last.In addition,P.minuta display some hormesis at about 0.05 mg·L-1 of Hg2＋.