Accumulation of methylmercury in the earthworm, Eisenia foetida, and its effect on regeneration.

The environmental contaminants mercury and methylmercury cause teratogenic, nervous, and renal damage in mammals (Venugopal and Luckey 1978). Methylmercury interferes with the normal development of tadpoles (Chang et al. 1974) and with the regeneration of fins in fish (Weis and Weis 1978) and limbs in crabs (Callahan and Weis 1983). Because mercury is highly toxic, it has been measured in a wide variety of wildlife and their foods. Earthworms provide an appropriate model for evaluating the environmental hazards of metals in soil (Ireland 1983), and they are also excellent organisms for studying the process of regeneration (Moment 1950, 1953, 1979). Two studies (Siegel et al. 1975, Helmke et al. 1979) have found that concentrations of mercury in earthworms were higher than those in the soil where they lived. This study investigates the accumulation of methylmercury in the earthworm, Eisenia foetida (Savigny), and its effect on regeneration after excision of the caudal end.