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The spotted bent-toed gecko Cyrtodactylus peguensis is one of the exploited reptiles in Thailand. In order to provide basic information for the digestive system of this species, we have examined histologically the gastrointestinal and accessory organs of C. peguensis using routine methods. The gastrointestinal region of this reptile started from the stomach and the intestine. The stomach was separated into fundic and pyloric regions. In both regions, the stomach wall was formed by four distinct tissue layers, including mucosa, submucosa, muscularis, and serosa layers. Mucous neck cells and oxynticopeptic cells were identified as glycoprotein-producing cells in the stomach by Periodic acid-Schiff (PAS) staining. The small and large intestines shared many histological characteristics, but the former contained more intestinal folds, while the latter had more PAS-positive goblet cells. Histological characteristics of accessory organs, liver and pancreas, were also provided. Overall, the gastrointestinal and accessory organs of C. peguensis were largely similar to those from other reptiles, but fine structural information will open up considerable opportunities to further studies related to the endocrinology, the physiology, and the conservation of this species.

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Many biodiversity hotspots are located in areas with a complex geological history, like Southeast Asia, where species diversity may still be far underestimated, especially in morphologically conservative groups like amphibians. Recent phylogenetic studies on the frog genusLeptobrachiumfrom Southeast Asia revealed the presence of deeply divergent mitochondrial clades inLeptobrachium hendricksonifrom Malaysia and Sumatra but populations from Thailand have not been studied so far. In this study, we re-evaluate patterns of intraspecific genetic diversity inL. hendricksonibased on the analysis of combined sequences of mitochondrial 12S and 16S genes (1310 base pairs) including for the first time samples from southern Thailand. Thai populations ofL. hendricksoniformed a distinct clade with respect to populations from central and southern Malaysia and Sumatra. High sequence divergence between lineages from Thailand, Malaysia and Sumatra suggests the possible presence of cryptic species inL. hendricksoni. Divergence withinL. hendricksonidates back to the late Miocene, around 6 Mya, when lineages from Thailand, north Malaysia and Sumatra split from a lineage in south Malaysia, at about the same time as rising sea levels isolated the Thai-Malay peninsula. Subsequent splits took place later in the Pliocene, around 4.5 and 2.6 Mya. Our results highlight the role of geological history in promoting population divergence and speciation.