A Study on the Ecological and Phylogenetic Factors Affecting the Light Reflectivity of Snake Shed Skin Scales

• Main Authors: Wang, Shih-Hao, 王士豪
• Other Authors: Tsai, Tein-Shun
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/8a37p7

碩士 === 國立屏東科技大學 === 野生動物保育研究所 === 106 === The color of the animal's body surface affects its ecological behavior. Many animals are hidden through color to avoid predators or increase the success rate of foraging. Snake body is covered by scales, which have important functions such as physical protection, light reflection or thermal exchange adjustment, crypsis or camouflage. The scale has the microstructure on its surface called microornamentation (MO), which may relate to ecological adaptation or phylogeny of snakes. In this study, I measured the reflectivity of scales on the shed skins of 176 snake species for different wavelengths of light (300 nm, 500 nm, 800 nm), to analyze the differences of light reflectivity of scales on snakes with different habitats (terrestrial, fossorial/burrowing, aquatic, semi-aquatic, arboreal), dorsal body patterns (single color, mottled, banded, striped), families (Cylindrophiidae, Boidae, Colubridae, Elapidae, Pythonidae, Viperidae, Xenopeltidae, Lamprophiidae, Homalopsidae, Pareatidae, Xenodermatidae, Typhlopidae), MO types, scale thickness, and direction of incident light. I hypothesized that the light reflectivity of snake scales is affected by both ecological and phylogenetic factors. The results showed that 1) the dorsal scales of snakes with mottled body pattern displayed lower light reflectance, while the dorsal scales of snakes with banded body IV pattern presented higher light reflectivity; 2) The light reflectivities of scales on aquatic snakes and semi-aquatic snakes were different from those with other habitat types; 3) the reflectivities of scales from snakes of different families were also different; 4) the reflectivity was related to the MO on scales; 5) the reflectivities of scales with different directions of incident light were different. The phylogenetic regression modeling also showed that the better models predicting light reflectivity of scales included both ecological and phylogenetic factors, where the effects of MO for dorsal scales or habitat for ventral scales dominated.