Mercury and selenium in developing and mature fruiting bodies of Amanita muscaria

Both mercury (Hg) and selenium (Se) occur in many mushroom species, but the morphological distribution of these elements during different developmental stages of the fruiting bodies is not known. Although Amanita muscaria can be consumed after suitable processing, they are often ignored by mushroom foragers, leaving an abundance for investigative study. Multiple specimens in each of six developmental stages (button to fully mature) were collected in excellent condition during a single morning from the same forested location and composited. With an average of 30 specimens per composite, and low temporal, spatial, and measurement uncertainty, the data are likely to be representative of the typical concentrations of Hg and Se for each developmental stage. Hg (range 0.58-0.74 mg kg^-1 dry weight cap; 0.33 to 0.44 mg kg^-1 dw stipe) and Se (range 8.3-11 mg kg^-1 dw cap; 2.2 to 4.3 mg kg^-1 dw stipe) levels were observed to vary during the developmental stages, and the variability may relate to the demands in growth. In common with some other species, the lower stipe concentrations may be consistent with nutrient/contant transport and support functions. Both Hg and Se levels were lowest during periods of maximum sporocarp growth. Selenium occurs at almost an order of magnitude greater levels than Hg. Due to its role in mitigating the effects of Hg toxicity, this property is of significance to those who consume the species either for nutritional, medicinal, or recreational purposes, although the losses of both these elements during processing are not known.