单独与混合暴露条件下褶纹冠蚌对Cu、Zn的积累与分布

采用室内模拟方法,在单独与混合暴露条件下研究了褶纹冠蚌(Cristaria plicata)对Cu、Zn的积累与分布特征.结果表明:褶纹冠蚌对水环境中的Cu、Zn具有良好的积累能力,持续暴露8d内,体内各组织重金属积累量基本呈线性上升,其中鳃与外套积累速率最快(p<0.05).Cu在褶纹冠蚌鳃、内脏团和生殖腺中的积累速率与Zn之间存在显著差异(p<0.05),且Cu、Zn之间在各组织中的积累拮抗作用明显.暴露前,Cu含量在褶纹冠蚌体内依次为:生殖腺>外套、内脏团>鳃、足>肌肉(p<0.05),变化幅度为10倍左右;Zn含量依次为:鳃>内脏团>生殖腺>足、外套>肌肉(p<0.05),变化幅度为4倍左右.暴露后,外套和鳃对Cu、Zn的积累量最高,且Cu、Zn含量在不同组织间的变化幅度明显增加.暴露前后,Cu含量在不同组织间的变化幅度均高于Zn.不同暴露条件下,褶纹冠蚌不同组织对Zn的浓缩系数(BCF)明显高于Cu.

Accumulation and Distribution of Copper and Zinc in the Freshwater Mussel, Cristaria Plicata, Exposed to Individual and Mixed Metals

Characteristics of accumulation and distribution of Cu and Zn in the freshwater mussel,Cristaria plicata,exposed to individual and mixed metals were investigated under the laboratory conditions.Results showed that the Cristaria plicata mussel could concentrate Cu and Zn in each soft tissue,the contents in which linearly increased with exposure times from 0 to 8 days.The tissues of gill and mantle accumulated Cu and Zn more rapidly than the other tissues(p< 0.05).Significant differences in accumulation rates between Cu and Zn were found at the tissues of gill,viscera and gonad(p <0.05)and the interaction of the two metals during accumulation was antagonistic.Before the metal exposure,metal contents in different tissues were with the sequences of gonad >mantle,viscera >gill,foot >muscle and the contents varied 10-fold range for Cu(p<0.05),and gill>viscera>gonad>foot,mantle>muscle and the contents varied 4-fold range for Zn(p <0.05).The metal exposures caused Cu and Zn contents reached the highest values in the mantle and gill respectively and the differences in Cu contents and Zn contents among each tissue were improved.The ranges of Cu contents varied in different tissues were higher than that of Zn contents varied before and after the exposure.At the different metal exposures,the bioconcentration factor(BCF)of Zn is higher than that of Cu obviously in each tissue of the test mussel.