Toxicity of methylmercury,mercuric chloride,and lead in killifish (Fundulus heteroclitus) from Southampton,New York

We have previously found great differences in susceptibility to teratogenic effects of methylmercury (meHg) among batches of eggs produced by different females of Fundulus heteroclitus. In the present study we investigated the relationships of resistance to meHg by a batch of eggs with other parameters of resistance. There was a positive correlation between embryonic meHg resistance and HgCl₂ resistance, although HgCl₂ generally caused less severe defects at a given dose level. The batches that were more susceptible to meHg had a greater uptake of mercury than the more resistant batches. There was a negative correlation of meHg resistance and Pb resistance (as measured by a skeletal index hatching), however. There was a positive correlation of meHg resistance of embryos and the subsequent meHg resistance of larvae after hatching.