Evaluation of the effectiveness of cryptic coloration of the Carolina anole’s skin

  • A. B. Kiladze A. N. Severtsov Institute of Ecology and Evolution, Russian Academy of Sciences
Keywords: adaptations; skin camouflage index; pigmentation; protective coloration; computational biology.


Cryptic coloration of animals’ integument is one of the effective adaptations that allow them to lead an active lifestyle while being protected from natural enemies due to visual disguise. This is achieved by the similarity of body color of a particular individual to the background of various substrates in its environment. The morphological and functional basis of cryptic coloration in vertebrates, including reptiles, is ensured by the skin pigmentation. Using bioinformatic methods, we calculated the skin camouflage index of the Carolina anole (Anolis carolinensis Voigt, 1832) in various conditions of its habitat. The skin camouflage index (Ic) is the ratio of the sum of the average values of rgb coordinates of the skin color to the sum of the average values of rgb coordinates of the color of the external substrate. Ic satisfies the effective level of adaptation to habitat conditions if it falls within the range of 0.80–1.20. It has been shown that rgb-values of the dominant color of the dorsal skin of green anoles slightly differ from the similar parameters characteristic of the deciduous habitat, which is reflected by Ic of its skin (0.94). In the brown anoles on a background of woody substrate, the Ic value of its skin (0.88) is also optimal, since it exceeds the lower limit (0.80), which indicates close values of the sums of the rgb coordinates of the skin color and the color of the external background. In the mixed green-brown anoles, the deciduous habitat is preferable to the woody one. In the first case, Ic (1.11) is in the optimum zone, and in the second case, Ic (0.70) goes beyond the lower limit of the optimum, which indicates a greater vulnerability of the animal to external threats. We have confirmed the relativity of visual hiding of the skin that is effective only in the habitat conditions in which the camouflage abilities of the skin manifest as fully as possible.


Allen, J. J., Akkaynak, D., Sugden, A. U., & Hanlon, R. T. (2015). Adaptive body patterning, three-dimensional skin morphology and camouflage measures of the slender filefish Monacanthus tuckeri on a Caribbean coral reef. Biological Journal of the Linnean Society, 116(2), 377–396.

Amdekar, M. S., & Thaker, M. (2019). Risk of social colours in an agamid lizard: Implications for the evolution of dynamic signals. Biology Letters, 15(5), 20190207.

Bagnara, J. T., Taylor, J. D., & Hadley, M. E. (1968). The dermal chromatophore unit. The Journal of Cell Biology, 38(1), 67–79.

Bagnara, J. T., & Matsumoto, J. (2006). Comparative anatomy and physiology of pigment cells in nonmammalian tissues. In: Nordlund, J. J., Boissy, R. E., Hearing, V. J., King, R. A., Oetting, W. S., & Ortonne J.-P. (Eds.). The pigmentary system: Physiology and pathophysiology. Second edition. Blackwell Publishing Ltd, Oxford. Pp. 11–59.

Belintsev, B. N. (1991). Fizicheskie osnovy biologicheskogo formoobfazovaniya [Physical foundation of biological morphogenesis]. Nauka, Moscow (in Russian).

Beltrán, I. (2019). Diurnal colour change in a sexually dimorphic trait in the Andean lizard Anolis heterodermus (Squamata: Dactyloidae). Journal of Natural History, 53, 45–55.

Benton, M. J., Dhouailly, D., Jiang, B., & McNamara, M. (2019). The early origin of feathers. Trends in Ecology and Evolution, 34(9), 856–869.

Bond, A. B. (2007). The evolution of color polymorphism: Crypticity, searching images, and apostatic selection. Annual Review of Ecology, Evolution, and Systematics, 38, 489–514.

Chernova, O. F., & Kiladze, A. B. (2014). Symmetry in topography and microstructure of vertebrate skin derivatives. Paleontological Journal, 48, 1284–1294.

Chernova, O. F., & Kiladze, A. B. (2019). Heterochrony as the basis for inter- and intraspecific diversity of skin in vertebrates. Biology Bulletin Reviews, 9(2), 174–189.

Claussen, D. L., & Art, G. R. (1981). Heating and cooling rates in Anolis carolinensis and comparisons with other lizards. Comparative Biochemistry and Physiology, Part A: Physiology, 69(1), 23–29.

Cott, H. B. (1940). Adaptive coloration in animals. Methuen & Co. Ltd., London.

Di-Poï, N., & Milinkovitch, M. C. (2016). The anatomical placode in reptile scale morphogenesis indicates shared ancestry among skin appendages in amniotes. Science Advances, 2, e1600708.

Endler, J. A. (2006). Disruptive and cryptic coloration. Proceedings of the Royal Society B: Biological Sciences, 273(1600), 2425–2426.

Farrell, P. (2019). Math adventures with Python: An illustrated guide to exploring math with code. No Starch Press, San Francisco.

Gardner, A. (2009). Adaptation as organism design. Biology Letters, 5, 861–864.

Ghiselin, M. T. (1966). On semantic pitfalls of biological adaptation. Philosophy of Science, 33, 147–153.

Gierer, A., & Meinhardt, H. (1972). A theory of biological pattern formation. Kybernetik, 12(1), 30–39.

Graeter, G. J. (2008). Green anole. In: Jensen, J. B. (Ed.). Amphibians and reptiles of Georgia. University of Georgia Press, Athens. Pp. 296–298.

Hadley, M. E., & Goldman, J. M. (1969). Physiological color changes in reptiles. The American Zoologist, 9, 489–504.

Heatwole, H. (1968). Relationship of escape behavior and camouflage in anoline lizards. Copeia, 1968(1), 109–113.

Henry, E., Brewer, J., Mougey, K., & Perry, G. (2008). The Texas horned lizard in Central and Western Texas. Iguana, 15(4), 205–211.

Jones, M. J., & Rehg, J. M. (2002). Statistical color models with application to skin detection. International Journal of Computer Vision, 46(1), 81–96.

Kiladze, A. B., & Chernova, O. F. (2014). Symmetry and asymmetry of configuration and structure of vertebrate skin. Paleontological Journal, 48, 1295–1302.

Kiladze, A. B., & Chernova, O. F. (2018). Adaptive peculiarities of pigmentation in the redbelly rock agama Paralaudakia erythrogastra (Nikolsky, 1896) (Agamidae). Ukrainian Journal of Ecology, 8(4), 248–251.

Landreneau, E. B. (2011). Scales and scale-like structures. Dissertation. Texas A&M University, College Station. Pp. 32–33.

Losos, J. B. (2009). Lizards in an evolutionary tree: Ecology and adaptive radiation of anoles. University of California Press, Berkeley.

Macedonia, J. M., James, S., Wittle, L. W., & Clark, D. L. (2000). Skin pigments and coloration in the Jamaican radiation of Anolis lizards. Journal of Herpetology, 34(1), 99–109.

Mäthger, L. M., Denton, E. J., Marshall, N. J., & Hanlon, R. T. (2009). Mechanisms and behavioral functions of structural coloration in cephalopods. Journal of the Royal Society Interface, 6(Suppl. 2), S149–S163.

Merilaita, S. (2003). Visual background complexity facilitates the evolution of camouflage. Evolution, 57(6), 1248–1254.

Morrison, R. L., Sherbrooke, W. C., & Frost-Mason, S. K. (1996). Temperature-sensitive, physiologically active iridophores in the lizard Urosaurus ornatus: An ultrastructural analysis of color change. Copeia, 1996(4), 804–812.

Murphy, J. B. (2017). Cuban herps. Herpetological Review, 48(3), 582–588.

Needham, A. E. (1974). The functions of integumental zoochromes. In: The significance of zoochromes. Zoophysiology and Ecology, 3. Springer, Berlin, Heidelberg. Pp. 131–161.

Norris, K. S. (1967). Color adaptation in desert reptiles and its thermal relationships. In: Milstead, W. W. (Ed.). Lizard ecology: A symposium. University of Missouri Press, Kansas City. Pp. 162–229.

Saenko, S. V., Teyssier, J., van der Marel, D., & Milinkovitch, M. C. (2013). Precise colocalization of interacting structural and pigmentary elements generates extensive color pattern variation in Phelsuma lizards. BMC Biology, 11, 105.

Sanchez, E., Gippner, S., Vences, M., Preißler, K., Hermanski, I. J., Caspers, B. A., Krause, E. T., Steinfartz, S., & Kastrup, F.-W. (2018). Automatic quantification of colour proportions in dorsal black-and-yellow coloured amphibians, tested on the fire salamander (Salamandra salamandra). Herpetology Notes, 11, 73–76.

Schneider, M. R., Schmidt-Ullrich, R., & Paus, R. (2009). The hair follicle as a dynamic miniorgan. Current Biology, 19(3), R132–R142.

Sigmund, W. R. (1983). Female preference for Anolis carolinensis males as a function of dewlap color and background coloration. Journal of Herpetology, 17(2), 137–143.

Stevens, M., Párraga, C. A., Cuthill, I. C., Partridge, J. C., & Troscianko, T. S. (2007). Using digital photography to study animal coloration. Biological Journal of the Linnean Society, 90(2), 211–237.

Stevens, M., & Merilaita, S. (2009). Animal camouflage: Current issues and new perspectives. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1516), 423–427.

Stevens, M., & Merilaita, S. (2011). Animal camouflage: Function and mechanisms. In: Stevens, M., & Merilaita, S. (Eds.). Animal camouflage: Mechanisms and function. Cambridge University Press, New York. Pp. 1–16.

Stuart-Fox, D., & Moussalli, A. (2009). Camouflage, communication and thermoregulation: Lessons from colour changing organisms. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 364(1516), 463–470.

Talbot, J. J. (1977). Habitat selection in two tropical anoline lizards. Herpetologica, 33, 114–123.

Taylor, J. D., & Hadley, M. E. (1970). Chromatophores and color change in the lizard, Anolis carolinensis. Zeitschrift fur Zellforschung und mikroskopische Anatomie, 104(2), 282–294.

Teyssier, J., Saenko, S. V., van der Marel, D., & Milinkovitch, M. C. (2015). Photonic crystals cause active colour change in chameleons. Nature Communications, 6, 6368.

Turing, A. M. (1952). The chemical basis of morphogenesis. Philosophical Transactions of the Royal Society of London. Series B, Biological Sciences, 237(641), 37–72.

Vitt, L. J. (1981). Lizard reproduction: Habitat specificity and constraints on relative clutch mass. The American Naturalist, 117(4), 506–514.

Yang, J., Lu, W., & Waibel, A. (1997). Skin-color modeling and adaptation. Lecture Notes in Computer Science, 687–694.

How to Cite
Kiladze , A. B. (2019). Evaluation of the effectiveness of cryptic coloration of the Carolina anole’s skin . Regulatory Mechanisms in Biosystems, 10(3), 320-326. https://doi.org/10.15421/021950