Chromosomal description of three Dixonius (Squamata, Gekkonidae) from Thailand

Chromosomal characteristics and karyological analysis of three Dixonius, including D. hangseesom, siamensis melanostictus, from Thailand were studied. Chromosome preparations conducted by squash technique bone marrow testis. Conventional Giemsa’s staining Ag-NOR banding techniques applied to stain the chromosome. The results showed that diploid chromosomes are 2n=40, for hangseesom siamensis; 2n=42, melanostictus. fundamental number (NF) is 42 in 44 types 2 metacentrics 38 telocentrics siamensis, while karyotype melanostictus comprised acrocentrics 40 telocentrics. In NORs located near centromere on long arm telocentric chromosome pair 13. Although, situated subtelomeric region 8. There no sex differences karyotypes between males females these geckos species. We found during metaphase I II male meiosis homologous synapsis 20 bivalents haploid (n=20). Moreover, 21 (n=21). Their formulas as follows: (2n=40): Lm2 + Lt2 Mt4 St32, Lt6 St28, (2n=42): La2 Lt12 St24.