The phylogenetic relationship among two species of genus Nebo (Scorpiones: Diplocentridae) from Saudi Arabia and Middle East.

Background: The genus Nebo has been identified as a medically important scorpion species distributed across Arabia and the Middle East. However, its taxonomic status remains unclear.

Aim: The molecular phylogeny of two Nebo species from Saudi Arabia and comparative sequences from Palestine is presented based on the mitochondrial cytochrome oxidase subunit I (COI) gene.

Methodology: Scorpion specimens were collected from two different localities, mainly the Southern part of Saudi Arabia. Then, DNA was extracted, amplified using invertebrate universal primers, and sequenced to identify the COI gene. The obtained sequences were analyzed, and phylogenetic trees based on maximum parsimony, neighbor-joining, and Bayesian inference were constructed.

Results: The inferred phylogeny indicates the monophyletic status of the family Diplocentridae and its subfamily Nebinae and Diplocentrinae. Also, the phylogenetic analyses support the existence of interspecific and intraspecific variations among/ within Nebo hierichonticus and Nebo yemenensis which may indicate distinct species.

Conclusion: Further morphological studies with additional specimens from the Arabian Peninsula may reveal possible undiscovered and cryptic species.