Morphometric and meristic diversity of the species Androctonus crassicauda (Olivier, 1807) (Scorpiones: Buthidae) in Saudi Arabia

Abstract

Intraspecific molecular and morphological variations among geographically isolated populations are useful for understanding the evolutionary processes, which is considered early stage of allopatric speciation. Also, the knowledge of the regional variation of scorpion venom composition is needed to improve antivenom therapeutic management. Androctonus crassicauda (Olivier, 1807) is the most common and medically important species in Arabia and the Middle East. Therefore, this study aimed to investigate the geographic morphological variation among A.crassicaudapopulations, regarding its geographical distribution in unexplored arid regions in Saudi Arabia. Samples were collected and examined morphologically under a dissecting microscope from different four eco-geographical regions. The results of ANOVA and multivariate statistical analyses provide strong evidence of geographical variation. The two populations from OTU3 and OUT4 showed the greatest degree of morphological difference from populations of OUT1 and OUT2. Each OTU3 and OTU4 populations showed significant speciation without overlapping in the two groups, while the remaining overlapped groups comprised two other populations. Several body variables influenced male separation, including carapace posterior width, metasoma 3rd length, and metasoma 2nd length. For females, telson length, metasoma 1st width, and sternite 7th width were highly influential variables. Such variation may suggest the existence of cryptic taxa within A. crassicauda populations in Saudi Arabia. Moreover, metasoma ratios can be used as good indicators in intraspecific variation studies of Scorpions.

Scorpions of the State of Kuwait

“…The status of Androctonus crassicauda in Kuwait deserves a closer examination. Alqahtani et al (2022) showed that the populations of this species in Saudi Arabia have several distinct forms, and those from the North Arabian Desert are distinct from those of the Central Arabian Desert and other population in the south and western Saudi Arabia, suggesting the existence of different species within the A. crassicauda complex. The Kuwaiti Androctonus populations should be compared with A. sumericus.…”

Androctonus tihamicus sp. nov. from the Mecca Province, Saudi Arabia (Scorpiones, Buthidae)

“…nov., and this record probably was the new species. In molecular and morphometrical investigations, Alqahtani et al (2022a , b , c ) referred to the existence of three distinct clusters of A. crassicauda populations collected from different ecogeographical regions in Saudi Arabia, and the Arabian clade is placed as a basal clade to Turkey and Iran sequences.…”

“…The genus has 36 valid species ( Rein 2023 ), of which most species are known to deliver severe stings. Androctonus is also very taxonomically confused due to great intraspecific morphological and molecular variation (Ben Ali et al 2000; Lourenço 2005 ; Lourenço and Qi 2006 , 2007 ; Lourenço 2008 ; Othmen et al 2009 ; Alqahtani et al 2022a , b ). As already shown by Hendrixson (2006) and Alqahtani et al (2019) , several Androctonus species are widely distributed in Saudi Arabia, where they inhabit diverse habitats.…”