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Material properties of the skin of the Kenyan sand boa Gongylophis colubrinus (Squamata, Boidae)

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Abstract

On the basis of structural data, it has been previously assumed that the integument of snakes consists of a hard, robust, inflexible outer surface (Oberhäutchen and β-layer) and soft, flexible inner layers (α-layers). The aim of this study was to compare material properties of the outer and inner scale layers of the exuvium of Gongylophis colubrinus, to relate the structure of the snake integument to its mechanical properties. The nanoindentation experiments have demonstrated that the outer scale layers are harder, and have a higher effective elastic modulus than the inner scale layers. The results obtained provide strong evidence about the presence of a gradient in the material properties of the snake integument. The possible functional significance of this gradient is discussed here as a feature minimizing damage to the integument during sliding locomotion on an abrasive surface, such as sand.

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Acknowledgments

Dr. Guido Westhoff (University of Bonn, Germany) provided frozen snakes and valuable comments on snake biology. S.G. was supported in this work by the Federal Ministry of Education, Science and Technology, Germany (BMBF project Biona 01RB0812A). Animal care for the live G. colubrinus was provided by M.-C. Klein. The experiments comply with the “Principles of animal care”, publication no. 86–23, revised 1985 of the National Institute of Health and also with the current laws of Germany. Figure 1a was reproduced/adapted with permission from The Journal of Experimental Biology, Barbakadze N, Enders S, Gorb S, Arzt E (2006) Local mechanical properties of the head articulation cuticle in the beetle Pachnoda marginata (Coleoptera, Scarabaeidae). J Exp Biol 209:722–730. doi:10.1242/jeb.0206.

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Authors and Affiliations

  1. Department of Functional Morphology and Biomechanics, Zoological Institute of the University of Kiel, Am Botanischen Garten 1-9, 24098, Kiel, Germany

    Marie-Christin G. Klein & Stanislav N. Gorb

  2. Evolutionary Biomaterials Group, Max Planck Institute for Metals Research, Heisenbergstr. 3, 70569, Stuttgart, Germany

    Marie-Christin G. Klein, Julia K. Deuschle & Stanislav N. Gorb

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  1. Marie-Christin G. Klein
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  2. Julia K. Deuschle
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  3. Stanislav N. Gorb
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Correspondence to Marie-Christin G. Klein.

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Klein, MC.G., Deuschle, J.K. & Gorb, S.N. Material properties of the skin of the Kenyan sand boa Gongylophis colubrinus (Squamata, Boidae). J Comp Physiol A 196, 659–668 (2010). https://doi.org/10.1007/s00359-010-0556-y

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