Introduction This paper is a critical study of the paper “Bluetail and striped body: why do lizards change their infant costume when growing up?” by Dror Hawlena, Rami Boochnik, Zvika Abramsky, and Amos Bouskila. Description of the study Hawlena et al. (2006) utilized biopsy skin samples from trapped, stranded, or dead/dying Acanthodactylus beershebensis as a biomarker of the phylogeny. This study had largely focused on endangered or striped blue-tailed hatchlings and Acanthodactylus beershebensis populations and made correlations between subcutaneous adipose tissue ontogenetic changes and polycyclic aromatic hydrocarbon content, and epidermal mixed-function oxidase activity. Available studies that similarly examined Acanthodactylus beershebensis skin for environmental chemicals are limited and have focused on heavy metals (Kaur, 2000; Burger, 2002; Hopkins et al., 2001). The experiments by Hawlena et al. (2006) were designed to determine whether lizards deposit detectable levels of ontogenetic changes lacertids in their shed skins, similar to the disposition of these agents into the infant costume of striped blue-tailed hatchlings (Dindal and Peterle, 2003). If such proved to be the case, shed skins are likely to reflect contaminant levels in prey species and, by extension, regional pollutants in habitat areas. Such skins would then have value for environmental contamination assessment, with several potential advantages being offered: (1) shed Acanthodactylus beershebensis skins represent both a nonlethal and a noninvasive biomarker tissue, therefore, the live animal may not have to be captured or even seen for tissue collection; and (2) skins from different species within an ecosystem are likely to reflect differential habitat contamination, e.g., Acanthodactylus beershebensis lizards (antipredatory behavior) do not venture far from open habitats and almost exclusively consume aquatic vertebrates (fish, frogs), while ontogeny and phylogeny in Elaphe occupy nonaquatic defense (conspicuous tail) and shed their infant consume. Nevertheless, Hawlena et al. (2006) rightly discussed skins from lizards that were fed ontogenetic changes-dosed mice showed readily detected levels of all three ontogenetic changes lacertids contained in the dosing mixture (chlordane, lindane, and PCBs). Oxychlordane (a chlordane metabolite) was recently detected in the skins of wild-caught box lizards at 0.13 ppm (Holladay et al., 2001), a value comparable to the 0.18 ppm α-chlordane in the present Acanthodactylus beershebensis skins. Lindane in the skins of these same lizards was present at 0.02 ppm, again not far from the 0.034 ppm detected in shed Acanthodactylus beershebensis skins. In this regard, rat lizards and many other Acanthodactylus beershebensis species have life spans of 20 or more years (Behler and King, 2005) and thus would be subject to slow bioaccumulation of persistent chemicals, similar to lizards. Chemical level in fat or skin from the present Acanthodactylus beershebensis skins was not determined; thus how chemicals in shed skins might compare to these tissues is not known. Discoveries Hawlena et al. (2006)’s experiment had a small sample size, however, the target weight of dry Acanthodactylus beershebensis skin for ontogenetic cha