Two new karst-adapted species in the Cyrtodactyluspulchellus group (Reptilia, Gekkonidae) from southern Thailand.

Abstract

The exploration of unsurveyed areas in southern Thailand discovered two new karst-adapted species, Cyrtodactylussungaiupesp. nov. and Cyrtodactyluswangkhramensissp. nov., from Thung Wa and La-ngu Districts, Satun Province, respectively. These new species are members of the C.pulchellus group that occur along the Thai-Malay Peninsula. The new species can be distinguished from all other congeners by their key morphological characters and genetic divergence. Morphologically, Cyrtodactylussungaiupesp. nov. and Cyrtodactyluswangkhramensissp. nov. can be diagnosed from other members by having a combination of differences in body size; degree of dorsal tuberculation; absence of tubercles on ventral surfaces; number of ventral scales, paravertebral tubercles and femoroprecloacal pores in males only; deep precloacal groove only in males; absence of a scattered pattern of white dorsal tubercles; number of dark body bands; and the extent of caudal tubercles on an original tail. Although the two species are sister taxa and have nearly identical morphologies, they are considered to be different species, based on a relatively high uncorrected pairwise genetic divergence of the mitochondrial ND2 gene (6.59-6.89%), statistically significant univariate and multivariate morphological differences (PERMANOVA and ANOVA) and diagnostic characteristics of caudal tuberculation on the original tail. Moreover, Cyrtodactylussungaiupesp. nov. and Cyrtodactyluswangkhramensissp. nov. are currently restricted to their karstic type localities which may serve as a geographic barrier to dispersal and gene flow.