不同价态Mn离子对刺参幼参急性毒性效应及富集作用

静水条件下,研究了Mn2+与Mn7+对刺参幼参行为和存活的影响,并分析了其在幼参体内的富集状况。结果表明,幼参在0.8 ~ 16 mg/L浓度范围内的Mn2+暴露96 h后死亡率均为0.0%,Mn2+在此浓度范围内无明显的急性毒性作用;但暴露于0.1 ~ 6.5 mg/L Mn7+中时,幼参的死亡率随浓度和暴露时间增加而升高。暴露48 h时,幼参的死亡率与Mn7+的浓度呈极显著正相关(P 0.01),Mn7+浓度高于0.5 mg/L时即对幼参表现出明显的急性毒性作用,其安全浓度(SC)为0.31 mg/L,Mn7+对幼参的急性毒性作用强于Mn2+。随着水体中Mn2+与Mn7+浓度的增加,幼参体内Mn元素含量和累积速率均逐渐升高,但富集系数变化存在较大差异。Mn7+在幼参体内的富集作用强于Mn2+。

Acute toxicity and accumulation of Mn ions with different valences on larval Apostichopus japonicas

Using static bioassay test, the acute toxicity of Mn2+ and Mn7+ on behavior and survival of juvenile sea cucumber Apostichopus japonicas was studied, furthermore, the accumulation in Ap. japonicas was also analyzed. The results showed that at 96 h of exposure, the mortality rates of Ap. japonicas were 0.0 % in all groups of Mn2+ treatment, no significant acute toxicity of Mn2+ was found within the experimental concentration range of 0.8 ~ 16 mg/L; However, when exposed to Mn7+ within the range of 0.1 ~ 6.5 mg/L, the mortality rate increased with the Mn7+ concentration and exposure time. At 48 h of exposure, the mortality rate of larval Ap. japonicas showed a significant positive correlation with Mn7+ concentration (P 0.01). Mn7+ at concentrations higher than 0.5 mg/L showed the significant acute toxicity, and its safety concentration (SC) for the juvenile sea cucumber was 0.31 mg/L. Therefore, Mn7+ had the stronger acute toxicity than Mn2+ to Ap. japonicas. With increasing concentrations of Mn2+ and Mn7+, the Mn content and accumulation rates in juvenile bodies gradually increased, but changes in bioconcentration factor differed between Mn2+ and Mn7+.