Nondestructive indices of trace element exposure in squamate reptiles

Compared with birds, mammals, fish, and even amphibians, very little is kno wn about the effects of contaminants on reptiles. Recent evidence that many reptile populations may be declining has stimulated demand for toxicologic al studies of reptiles as well as development of nondestructive sampling te chniques useful for assessing and monitoring contaminant exposure. The curr ent study experimentally evaluated the utility of shed skins, tail clips, a nd blood samples as nondestructive indices of trace element exposure in ban ded water snakes, Nerodia fasciata. For 13.5 months, snakes were either fed fish from a coal ash-contaminated site or uncontaminated food from a refer ence site. Snakes fed contaminated prey accumulated As, Cd, Se, Sr, and V i n various organs (i.e. liver, kidney, and/or gonads). Moreover, non-paramet ric discriminant function analysis revealed that snakes could be placed in two groups that reliably reflected their experimental diet based upon Se, S r, and As concentrations in tail clips, blood, and/or shed skins. We sugges t that nondestructive sampling techniques, particularly analyses of blood a nd tail clips, may be easily applied in evaluations of contaminant exposure in the field and laboratory and may prevent excessive destructive sampling of potentially threatened reptile species. (C) 2001 Elsevier Science Ltd. All rights reserved.