Bioaccumulation of Cd by a European lacertid lizard after chronic exposure to Cd-contaminated food

Abstract

Apart from analyses for elemental contaminants in field collected specimens, very little is known about the assimilation, accumulation and toxic effects of inorganic contaminants in reptiles. This study examined the chronic accumulation of Cd in a European lacertid lizard (Podarcis carbonelli) following dietary provision of an environmentally realistic concentration of Cd for 21 weeks. Lizards were provided with Cd that had either been biologically incorporated into crickets, or as Cd(NO3)(2) added superficially to crickets just prior to feeding. Among both treatment groups Cd accumulated in tissues in the following order of concentration: gut > liver > kidney > carcass. The majority of the Cd was retained within the gut, and transfer to internal organs was low. Morphological indices, brain and plasma cholinesterase activities, gut and liver metallothionein content, and standard metabolic rate were measured as biomarkers of exposure and effect; however, no differences between control lizards and Cd-treated lizards were observed. (C) 2007 Elsevier Ltd. All rights reserved.