Acute Toxicity of Cadmium and Nickel to Three Marine Copepods

The present study aims to evaluate the toxicity of two heavy metals, cadmium (Cd) and nickel (Ni), to three marine copepods with different ecological habitats. Semi-static acute toxicity tests of Cd and Ni were conducted in our laboratory (Xiamen University) for 48 h with the harpacticoid copepod Tigriopus japonicus, cyclopoida copepod Apocyclops borneoensis, and calanoid copepod Acartia pacifica. Cadmium showed higher toxicity for the three copepods tested with 48-h LC50 values at 12.1, 1.6 and 0.1 mg L-1 Cd, respectively. While, that of nickel were 17.70, 13.05 and 2.36 mg L-1 Ni, respectively. Cadmium and Nickel were more toxic to the pelagic copepod A. pacifica, followed by A. borneoensis and T. japonicus. The results suggested that the pelagic calanoid copepod A. pacifica may be used as a benchmark species for assessing the toxic effects of heavy metals.