Resumo

BARRERA-ESCORCIA, Guadalupe  e  WONG-CHANG, Irma. MEAN LETHAL BODY CONCENTRATION OF CADMIUM IN Crassostrea virginica FROM A MEXICAN TROPICAL COASTAL LAGOON. Rev. Int. Contam. Ambient [online]. 2005, vol.21, n.2, pp.55-62. ISSN 0188-4999.

The acute effect of cadmium on Crassostrea virginica from the Mandinga Lagoon, México, was evaluated and related to corporal metal accumulation. The bioassay was performed with oysters exposed to lethal Cd concentrations, at temperature of 24.13 °C and salinity of 22.54 %o. The exposed organisms accumulated from 261.20 to 508.80 µgCd/g dry weight in average. The metal incorporated in organisms exposed to the highest Cd concentration was superior in oysters which died during the experiment, than in survivors. However biococentration factor was lower in the highest Cd concentrations. There was weight loss associated to the exposition and it was greater in survivors. Deterioration could be related to a greater metabolic effort to compensate the entrance of Cd. The mean lethal concentration, CdLC50-72h=24.87 mg/L, and the mean lethal body concentration, CdLBC50-72h=502.25 µg/g (4.47 µmol/g), had good adjustments to the Probit model. The body concentration, the bioconcentration factor and the LBC50 associated to the physical and chemical parameter values, particularly salinity and temperature, could constitute useful tools in the evaluation of the cadmium adverse effects in Mexican coastal areas.

Palavras-chave : oyster; metals; bioconcentration; Mandinga lagoon.