Abstract
The genetic structure of four populations of Androctonus crassicauda (Olivier, 1807) from different ecogeographical regions of Saudi Arabia was studied. To detect genetic differences among populations, the sequences of the cytochrome oxidase subunit I gene of 21 individuals of A. crassicauda from Saudi Arabia, and 11 sequences from Iran were utilised. The nucleotide and haplotype diversity were constructed. The results revealed a high level of haplotype and nucleotide diversity within all populations. A total of eighteen haplotypes were identified, 17 of which were unique. Molecular variance analysis (AMOVA) indicated a high genetic diversity reflecting differences between the populations. Fixation indices revealed significant genetic structure among all populations from Saudi Arabia and Iran. Also, the phylogenetic tree and the haplotype network analyses show the existence of three distinct clusters of A. crassicauda in Saudi Arabia and Iran.