Single and joint toxicity of four heavy metal ions on Mugilogobius chulae

Single and joint toxicity of four heavy metal ions,Hg2 +、Cr6 +、Cd2 +and Pb2 +,on Mugilogobius chulae at different developmental stages were studied. The results show that the toxicity sequence of four heavy metal ions to M. chulae was Hg2 + Cr6 + Cd2 + Pb2 +. The median lethal concentrations( LC50) of 48 h for Hg2 +、Cr6 +、Cd2 +and Pb2 +to 1 day-old fish were 0. 0013,5. 0,12. 2 and 313 mg / L,respectively. The sensitivity sequence of M. chulae at different developmental stages to four heavy metal ions was prelarva ﹥ middle larva ﹥ postlarva ﹥ juvenile ﹥ young. The toxicity of mixture Pb2 +-Cd2 +and Pb2 +-Cr6 +showed to be antagonistic for M. chulae in all stages. The safe concentration threshold of M. chulae to Hg2 +is 0. 013 μg / L. The ioint toxicity of Cr6 +-Cd2 +,Hg2 +-Cr6 +,Hg2 +-Cd2 +, Hg2 +-Pb2 +varied with the developmental stage. Hence in the revised marine water quality standard version,Hg2 +is strictly controlled. The prelarva is more sensitive than other to heavy metal ions and M. chulae is suited for toxicity assessment of heavy metal ions in water.