Zn^(2+)、Mn^(7+)对刺参幼参的急性毒性及富集作用研究

Study on the Acute Toxicity and Accumulation of Zn^(2+), Mn^(7+) on the Juvenile Sea Cucumber Apostichopus japonicas

在静水条件下,研究了Zn2+、Mn7+两种重金属离子对刺参幼参行为及其存活状况的影响,并分析了其在幼参体内的富集状况。结果表明:Zn2+、Mn7+单独处理时,幼参在Zn2+浓度低于0.4 mg/L或Mn7+浓度低于0.5 mg/L条件下暴露96 h后死亡率均为0.0%,表明在此对应浓度范围内两种金属离子均无明显的急性毒性作用;随浓度和暴露时间增加,幼参死亡率明显升高,其附壁率呈降低趋势。Zn2+对幼参的24、48、72 h的半致死浓度LC50分别为49.70、1.35、0.82 mg/L,安全浓度(SC)为0.14 mg/L;Mn7+对幼参的48、72、96 h的半致死浓度LC50分别为31.61、4.24、3.13 mg/L,SC为3.16 mg/L。因此,Zn2+对幼参的急性毒性作用强于Mn7+。随着水体中Zn2+与Mn7+浓度的增加,幼参体内重金属元素含量和累积速率总体呈升高趋势,而富集系数呈降低趋势,Zn2+的富集作用强于Mn7+。

Using static bioassay test, this paper studied the acute toxicity of Zn^2＋ and Mn^7＋ on behavior and survival status of the juvenile sea cucumber Apostichopus japonicas, furthermore, the accumulation in A. japonicas was also analyzed. The results showed that 96 h separating exposure to Zn^2＋ or Mn^7＋, the mortality rates of A. japonicas in Zn2＋under 0.4 mg/L and Mn^7＋under 0.5 mg/L were 0.0%, and no obvious acute toxici-ty was found within the above experimental concentration; The mortality rate increased with the increase of concentration and exposure time, but the adhesion rate decreased. The median lethal concentrations （ LC50） of Zn^2＋ in 24 h, 48 h and 72 h were 49.70, 1.35 and 0.82 mg/L respectively, and its safety concentration （SC） was 0.14 mg/L; The median lethal concentrations （LC50） of Mn^7＋ in 48 h, 72 h and 96 h were 31.61, 4.24 and 3.13 mg/L, and the SC was 3.16 mg/L. Therefore, it was concluded that Zn2＋had a stronger acute toxicity than Mn^7＋ on A. japonicas. With increasing concentrations of Zn^2＋ and Mn^7＋, the contents of hmetals and accumulation rates gradually increased, but the change of enrichment coefficient wsa contrary. It was indicated that Zn^2＋ showed the stronger accumulating process than Mn^7＋ on the juvenile sea cucumber.