镉在拟环纹豹蛛体内的积累动态

Accumulation dynamics of cadmium in wolf spider,Pardosa pseudoannulata

以拟环纹豹蛛为研究对象,通过田间试验探讨拟环纹豹蛛体内镉的生物积累特征,进而定量分析实际土壤镉含量与其上活动的拟环纹豹蛛体内镉含量间的关系.在为期70天的田间试验中,前42天拟环纹豹蛛体内镉的积累变化与染镉喂食量显著相关(P<0.01);后28天的饱和期内,其体内镉的积累量既不因停止摄取镉而减少,也不因继续摄取镉而增加,说明拟环纹豹蛛体内镉含量的富集饱和期为42天.通过实际受污染生境调查得到与田间试验一致的结论,即处于未饱和期的拟环纹豹蛛体内镉含量与其生境土壤镉含量存在极显著正相关.

To effectively utilize bio-indicator to predict heavy meatal contaminated environment at the earliest stage, Pardosa pseud-oannulata, also named wolf spider, was fed with cadmium （ Cd）-contaminated flies in the laboratory condition for 70 d, with the first 42 d being fed with Cd-contaminated flies and the last 28 d fed with uncontaminated ones. The number of flies eaten and changes in Cd concentrations and contents in P. pseudoannulata were recorded. Meanwhile, P. pseudoannulata and soil were sampled in Cd-contaminated farmland, basing on which the relationship between Cd concentrations in P. pseudoannulata and soil were determined. Results showed that a strong relationship existed between Cd concentrations in P. pseudoannulata and the amount of Cd supplied by feed at the first 42 nd day of feeding （ P〈0.01） . After 42 d, Cd level stayed contant in P. pseudoannulata regard-less of being fed with uncontaminated or Cd-contaminated flies, indicating that P. pseudoannulata reached the saturation level at the 42nd d. Moreover, Cd concentrations in P. pseudoannulata coincided well with Cd concentrations in the soil where they inhabited, suggesting that Cd concentrations in P. pseudoannulata was highly correlated with soil Cd before reaching the accumulative saturation level.