Magnesium and manganese uptake, accumulation and regulation by a terrestrial isopod, Porcellio spinicornis Say (Porcellionidae, isopoda, Crustacea).

Highest Mg concentration in whole intermoult, 7th growth-stage Porcellio spinicornis, exposed for 7 days to various Mg [367.39 ppb (carrot powder-control), 217.6 ppb (apple powder-control), 100, 150, 500, and 1000 ppm Mg, as well as two mixtures containing 500 ppm Mn + 150 ppm Mg and 500 ppm Mg + 500 ppm Mn)], and Mn concentrations [97.9 ppb (carrot powder-control), 2.0 ppb (apple powder-control), 100, 150, 500 and 1000 ppm)], was observed in males feeding on 500 ppm Mn + 150 ppm Mg, and lowest in females on 500 ppm dietary Mg. Highest tissue Mn concentration, on the other hand, was observed in males exposed to 1000 ppm dietary Mn, and lowest in females on 500 ppm Mg. Approximately 42% of the total tissue Mg was present in hepatopancreas and the remaining in other body tissues, including exoskeleton. In contrast, 78.55% Mn was stored in hepatopancreas and 21.4% in remaining body tissues. Differences between hepatopancreatic Mg levels were not significant between the two sexes, but differences in Mn levels between males and females were significant at P less than 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)