Morphological variation of garden fence lizard Calotes versicolor (Daudin, 1802) in Thailand

Abstract

The garden fence lizard, Calotes versicolor, is a common and widely distributed lizard throughout the Middle East, Far-East and Southeast Asia. Although this species displays variations in its morphology throughout its range, these variations have not been examined in many countries including Thailand. Thus, we examined 20 adult lizards, ten males and ten females from each of three sampling localities in each of northern and southern Thailand to document sexual and regional variations. Differentiation in characters between sexes and populations were tested by analysis of covariance (ANCOVA) and principle component analysis (PCA) for the mensural characters, Mann-Whitney U-test for meristic characters and chi-squared test for stripe patterns. Sexual dimorphism was found in both northern and southern populations. Males have a larger relative head size and longer relative limb lengths, whilst females exhibit a longer relative trunk length. The number of scale in males was also more prominent than in females. Females in both southern and northern Thailand populations have brighter patterns in paired dorsolateral stripe (DorsSt), forearm stripe (ForearSt) and paired nuchal spots (NucSpot) than the corresponding males. Geographic difference in mensural characters and stripe patterns was more prominent in males, but meristic characters were not clearly different. Males in the southern populations have a larger relative head size and longer relative limb lengths than those from the northern populations, but these differences were not found in females. No difference in stripe pattern was found between females from the northern and southern populations, whereas males in the southern populations have brighter patterns in dark bands on trunk (TrnkBand) and colored throat patch (ThroatPa) than those in the northern populations.