Hepatopancreas cadmium concentrations
Land snails are considered to serve as 'macroconcentrator' species for Cd given their exceptional ability to accumulate it in their tissues far above environmental levels (Dallinger et al., 1993). Several studies have examined the retention of dietary Cd in the soft tissues of C. aspersus under laboratory conditions, but not at exposure levels below 0.2 mg kg-1 DW (Russell, DeHaven & Botts, 1981; Laskowski & Hopkin, 1996; de Vaufleury et al., 2006). The similarity between cadmium concentrations measured in controls at different time points clearly demonstrates that ingestion of food was the only exposure path observed, confirming that the experiment was properly conducted. These values are close to those found in adult C. aspersus originating from relatively unpolluted areas, with normal levels of Cd in soils and/or vegetation (Menta & Parisi, 2001; Beeby & Richmond, 2002). As a result, small amounts of cadmium, such as those reported here for controls, are not …show more content…
aspersus. This is largely comparable with the results obtained in a previous experiment after four months of continuous exposure to 0.28 mg/kg dw Cd in the food (Laskowski & Hopkin, 1996). These data also suggest that C.aspersus adults may regulate internal Cd levels for such low, but field-relevant Cd concentrations. Indeed, such mechanisms are known to exist in terrestrial gastropods. For example, the grove snail Cepaea nemoralis (Linnaeus, 1758) was able to maintain stable cadmium concentrations in the soft tissues via excretion through mucus and faecal fluids when orally exposed to up to 0.3 mg kg-1 DW. dietary Cd for 38 days (Notten et al., 2006). Moreover, from these findings one can also infer that the hepatopancreas Cd content of C. aspersus adults over which this regulatory capacity is exceeded should lie around 12 mg kg-1
Land snails are considered to serve as 'macroconcentrator' species for Cd given their exceptional ability to accumulate it in their tissues far above environmental levels (Dallinger et al., 1993). Several studies have examined the retention of dietary Cd in the soft tissues of C. aspersus under laboratory conditions, but not at exposure levels below 0.2 mg kg-1 DW (Russell, DeHaven & Botts, 1981; Laskowski & Hopkin, 1996; de Vaufleury et al., 2006). The similarity between cadmium concentrations measured in controls at different time points clearly demonstrates that ingestion of food was the only exposure path observed, confirming that the experiment was properly conducted. These values are close to those found in adult C. aspersus originating from relatively unpolluted areas, with normal levels of Cd in soils and/or vegetation (Menta & Parisi, 2001; Beeby & Richmond, 2002). As a result, small amounts of cadmium, such as those reported here for controls, are not …show more content…
aspersus. This is largely comparable with the results obtained in a previous experiment after four months of continuous exposure to 0.28 mg/kg dw Cd in the food (Laskowski & Hopkin, 1996). These data also suggest that C.aspersus adults may regulate internal Cd levels for such low, but field-relevant Cd concentrations. Indeed, such mechanisms are known to exist in terrestrial gastropods. For example, the grove snail Cepaea nemoralis (Linnaeus, 1758) was able to maintain stable cadmium concentrations in the soft tissues via excretion through mucus and faecal fluids when orally exposed to up to 0.3 mg kg-1 DW. dietary Cd for 38 days (Notten et al., 2006). Moreover, from these findings one can also infer that the hepatopancreas Cd content of C. aspersus adults over which this regulatory capacity is exceeded should lie around 12 mg kg-1