Cu~（2＋）胁迫对单齿螺的毒性影响

以海生单齿螺（Monodonta labio）为受试生物,研究不同浓度Cu2＋胁迫下,Cu2＋对单齿螺的急性毒性、单齿螺对Cu2＋的富集性以及Cu2＋对单齿螺体内过氧化氢酶（CAT）和超氧化物歧化酶（SOD）活性的影响。结果表明,Cu2＋对单齿螺的96和72 h的半致死浓度〔ρ（LC50）〕分别为19.36和38.49 mg.L-1,安全浓度（ρs）为1.936 mg.L-1。单齿螺对Cu2＋的富集性随ρ（Cu2＋）的增加而增强,具有明显的剂量效应。当ρ（Cu2＋）为4.00 mg.L-1时,单齿螺对Cu2＋的累积量随处理时间的增加而增加,具有较明显的时间效应。各Cu2＋处理组单齿螺肝胰腺CAT活性均比对照（海水）组高,而且大多数处理组与对照组间差异均达显著水平（P〈0.05）或极显著水平（P〈0.01或P〈0.001）。但部分Cu2＋处理组单齿螺肝胰腺SOD活性低于对照组。

Toxic Effects of Copper on Monodonta labio.

Acute Cu toxicity and Cu enrichment of Monodonta labio under Cu^2＋ stress and effects of Cu^2 ＋ on CAT and SOD activities in the hepatopancreas of Monodonta labio were studied. Results show that the 96 and 72 h half lethal con- centration [p（ LCs0 ） ] of Cu2＋ to Monodonta labio were 19. 36 and 38.49 mg· L-1 , respectively. And the safe concentra- tion of Cu2 ＋ （px） to Monodonta labio was 1. 936 mg · L-1 Monodonta labio enhanceed its Cu enrichment when the p（ Cu2~ ） ranged from 0. 25 to 4. 00 mg· L-1. An obvious dose-dependent effect of Cu2＋ was observed on Monodonta la- bio. When p（ Cu2 ＋ ） was 4. 00 mg· L-1, Cu2 ＋ accumulation in Monodonta labio increased with the time of treatment, showing a obvious time-dependent effect. In all the Cu2＋-treated groups CAT activity in hepatopancreas of Monclonta labio were higher than those in the control. In most of the treatments, the differences were highly significant （ P 〈 0. 05 ） or ex- tremely significant （P 〈 0. 01 or P 〈 0. 001 ）. However, in some treatments, Monodonta labio showed lower hepatopancre- as SOD activity than they did in the control.