INORGANIC AND ORGANIC MERCURY UPTAKE AND LOSS BY THE CRAYFISH ORCONECTES-PROPINQUUS

Inorganic and organic Hg accumulation from food by the crayfish Orconectes propinquus was studied in the laboratory. Animals were fed pellets of dried cat food dosed in 1-mu-g g-1 dw with Hg-203 labeled HgCl2 and CH3HgCl over a two-week period. This was followed by a three-week depuration period which crayfish were fed uncontaminated food. At the end of each of these periods body tissues were analyzed for labeled Hg. Hg-203 uptake from HgCl2 followed the ranking: hepatopancreas > gills > exoskeleton > muscle. In all tissues there was evidence of Hg uptake from water via leaching from food although uptake was principally from food. Mercury uptake from CH3HgCl followed the ranking: gills > muscle > hepatopancreas > exoskeleton. Only Hg accumulated from HgCl2 by the hepatopancreas failed to depurate over the next three weeks. Mercury uptake by the hepatopancreas from CH3HgCl was negligible. Results suggest a more rapid turnover of Hg in crayfish than in finfish.