A New Method to Examine the Oberhautchen of Lizard Skin

Abstract

Scanning electron microscopy (SEM) is a powerful tool used in the study of lizard skin morphology and has allowed researchers to gain insight into the intricate structure of complex epidermal layers, an interesting part of which is the outer layer or oberhautchen. Methods involved in the preparation of samples for SEM are invasive and usually involve killing and preserving specimens. Here we present a new, simple, highly accurate method for the examination of living lizard epidermis using polyvinylsiloxane impression material and epoxy resin to create molds. We created molds of live Oedura castelnaui (Squamata: Diplodactylidae) using two different types of epoxy resin to compare their efficacy. Viscosity was the important factor determining whether there were artifacts in the mold, and the resin that created fewest artifacts was Epirez 123® (ITW Polymers & Fluids). We used Epirez 123® to create molds of Phyllurus ossa, P. amnicola, and Nephrurus levis (Squamata: Carphodactylidae), which all have ornate oberhautchen. We visually compared these with published images of hair sensors of congeners, and found that our method compared very favorably. Thus, this method can produce exceptional quality reproductions of complex microornamentations within the oberhautchen of living lizards.