Bioaccumulation and distribution of mercury in the hard clam, Meretrix lusoria (Bivalvia: Veneidae).

1. Total mercury concentration in whole soft parts of the hard clam, Meretrix lusoria, increased significantly with increasing exposure concentrations. It reached 4.247-7.084 and 9.956-13.643 micrograms T-Hg/g dry weight in 5 and 50 micrograms/l Hg mercury solution, respectively, against a background level of 1.824-0.577 micrograms T-Hg/g dry weight. 2. Bioconcentration factor was 4-6 times higher in 5 micrograms/l Hg than that of 50 micrograms/l Hg. An estimated biological half-life of 20.2 and 18.4 days in 5 and 50 micrograms/l Hg, respectively, were also obtained after 14 days uptake. 3. Accumulation of mercury in tissues of the clams was greater in the gills and viscera than in the mantle, adductor, foot, or hemolymph. 4. The amount of mercury present in the gills is related to be a linear relationship with the mercury content of viscera.