Toxicity of organic mercury compounds to the developing brine shrimp, Artemia

Mercury can be coupled to a wide variety of organic compounds but there is limited information concerning the influence of such substitutions on the toxicity of mercury within the marine environment. We therefore determined the effects of six organomercuries on the emergence and hatching of the brine shrimp, Artemia. The relative toxicities of the organic mercuries were unaffected by the ability of the compounds to ionize, whereas the sizes of the compounds appeared to be important. Thus, brine shrimp were equally sensitive to five of the organic mercuries while diphenylmercury, the largest of the organic mercuries tested, was the least toxic. In the presence of 0.1 microM diphenylmercury the final amount of hatching was similar to that in the absence of metal but in this situation there was an easily measured reduction in the rate of development. By determining the rates of emergence and hatching it is apparent that Artemia are adversely affected by organic mercuries at concentrations less than 0.1 microM, the lowest level examined in this study. The work extends our earlier findings with cadmium and zinc, supporting the proposal that Artemia is an excellent alternative to more complex, slow-growing animals for the study of biochemical/physiological aspects of marine pollution.