<![CDATA[Abstract. Chumpol P, Tanomtong A, Neeratanaphan L, Donbundit N, Ditcharoen S. 2026. First karyotypic characterization of the three Hemidactylus species (Gekkonidae, Squamata) from Thailand. Biodiversitas 27 (9): d270915. https://doi.org/10.13057/biodiv/d270915. This study reports the first karyotypic descriptions of Hemidactylus murrayi and Hemidactylus parvimaculatus and the first cytogenetic characterization of Hemidactylus garnotii from two provinces in Thailand. Chromosomes were prepared from bone marrow. Conventional Giemsa staining and Ag-NOR banding techniques were used for chromosomal analysis. These approaches enabled comparative evaluation of chromosome number, morphology, fundamental number, and the distribution of nucleolar organizer regions among the three examined species. H. garnotii had a diploid chromosome number of 2n = 38 with a Fundamental Number (FN) of 46, heteromorphic chromosomes tentatively interpreted as a putative ZW system and a karyotype formula of 2n(38) = 6m + 30t + ZW, while H. murrayi and H. parvimaculatus showed diploid numbers of 2n = 40 and FN = 74 and 64, respectively. Their karyotype formulae were 2n(40) = 8m + 6sm + 20a + 6t for H. murrayi and 2n(40) = 12m + 2sm + 10a + 16t for H. parvimaculatus. Nucleolar organizer regions (NORs) were localized near the centromere on one homolog of chromosome pair 4, while H. murrayi and H. parvimaculatus showed the NOR loci near the telomere on pairs 14 and 13, respectively. The observed variation in chromosome morphology and NOR position further demonstrates cytogenetic differentiation among these closely examined taxa. These cytogenetic findings expand the comparative karyological information available for Hemidactylus species and provide a foundation for future molecular cytogenetic and taxonomic studies within the genus.]]>
