The cumulation of methylmercury in fish (Poecilia reticulata).

Methylmercury labelled with mercury-203 was used for the investigation of the uptake and the release of methylmercury in fish. It has been found that methylmercury compounds adsorbed on fish food remain completely in fish and that they are released with the biological half-time of 110 +/- 20 days. The cumulation of methylmercury from water is very rapid: the cumulation constant is 237 +/- 67 days-1. Equations for the calculation of the concentration of methylmercury in fish were derived and compared with the uptake of phenylmercury and inorganic mercury.