Cadmium and zinc reversibly arrest development of Artemia larvae

Results are presented of experiments on the effects of cadmium and zinc on larvae of the brine shrimp, Artemia. Pre-nauplius larvae prior to hatching were much more sensitive to cadmium than were hatched nauplius larvae. At a concentration of 0.1 uM, cadmium retarded development and hatching of the larvae; higher concentrations inhibited hatching completely. Larvae arrested at the emergence stage survived for 24 h or more before succumbing to the effects of cadmium, and during this period the potentially lethal effect could be reversed by transferring the larvae to clean water. Similar effects were observed with zinc, although this metal was less toxic than cadmium at equivalent concentrations. Micrographs are included showing normal development of Artemia larvae, and abnormal development of larvae exposed to cadmium.