Toxic Effects Of Common Heavy Metals On Nibea Japonic And Palaemon Carincauda

By Static test method, acute toxicity tests ofCu²⁺and Cr⁶⁺to Nibea japonic andCr⁶⁺,Cu²⁺, Mn⁷⁺and Zn²⁺to Palaemon carincauda were carried out for96hours. Resultsshowed that the median lethal concentration ofCu²⁺to Nibea japonic in24,48,72and96hwas3.178mg/L,2.924mg/L,2.755mg/L and2.63mg/L respectively and the safeconcentration was0.0263mg/L. According to the chemical hazard classification criteriafor acute toxicity to fish.Cu²⁺was high toxic for Nibea japonic;The corresponding medianlethal concentration of Cr⁶⁺to Nibea japonic was4.18,3.60,3.17and3.01mg/L，its safeconcentration was0.03mg/L.96h LC50of Cr⁶⁺,Cu²⁺, Mn⁷⁺and Zn²⁺to Palaemoncarincauda were14.0mg/L,18.07mg/L、25.1mg/L and32.9mg/L respectively. Thesmaller LC50value shows that the toxicity was stronger. By96hLC50of them，the acutetoxicities of Cr⁶⁺、Cu²⁺、Mn⁷⁺and Zn²⁺were in the sequence of Cr⁶⁺＞Cu²⁺＞Mn⁷⁺＞Zn²⁺The joint toxicity experiments of Cr⁶⁺-Mn⁷⁺,Mn⁷⁺-Zn²and Cr⁶⁺-Zn²⁺to Palaemoncarincauda were carried out by Mark’s additive index method Results showed that inboth experiments of Cr⁶⁺-Mn⁷⁺and Mn⁷⁺-Zn²⁺, AI<0in24h,48h, and72h and96h. jointtoxicity appears to be antagonistic. In Cr⁶⁺-Mn⁷⁺and Mn⁷⁺-Zn²⁺were antagonistic too. Cr⁶⁺-Zn²⁺was synergetic in24h and48h, whereas in72h and96h was antagonistic.An acute exposure experiment of Cr⁶⁺on Nibea japonica was carried out by semi-staticbiological test method. The abnormal rates of micronucleus and nuclear in peripheral bloodcell, the activities of superoxide dismutase （SOD） and catalase （CAT） in liver weredetermined in6,12,24,72and96h respectively. The results showed that the abnormal ratesof micronucleus and nuclear exposed to Cr⁶⁺solution at different concentrations weresignificantly higher than those in control group（p＜0.05）. The nucleus abnormal rateswere commonly higher than micronucleus rate at the same Cr⁶⁺concentration. Theactivities of SOD and CAT had no significant change in the control group during theexperiment（P＞0.05）. Compared with the control group, activities of SOD and CAT hadgreatly changed in the test groups（p＜0.05）, which represented a tendency ofincrease-decrease-increase again within96hours.