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.

The description of the firefly reproductive structure is relatively under-researched. Therefore, we initially observed the differentiating stages of spermatogenesis in the adult male firefly, Pyrocoelia tonkinensis, which could be the very first report in Thailand. All firefly specimens gathered from Nakhon Si Thammarat province, Thailand, were processed using the standard histological technique. It was divulged that a pair of testicular structure with several sperm tubules was seen. The stage of spermatogonia within testis follicle could be divided into three main zones, namely zone I (growth), zone II (maturation), and zone III (transformation). In this process, each zone contained the differentiating stages of spermatogenesis, which was classified into six stages based on size differences and the histological organization (especially in the chromatin organization) including spermatogonia, primary spermatocytes, secondary spermatocyte, spermatids with two sub-steps, and spermatozoa. The detailed information about male P. tonkinensis reproduction could generate not only a baseline data to be better known but also contribute to the future works regarding ultrastructure and physiology of the reproductive system. This would then be supportive of the conservation and management of the firefly in Thailand.