19 March, 2014

A genetic study of the medical relevant genus Androctonus in North Africa

The genus Androctonus Ehrenberg, 1828 (Buthidae) contains the most medical important scorpions of North Africa. Because of this it is very important to study the different populations of Androctonus' taxonomy, venom composition and phylogeographical patterns.

Coelho and co-workers have now published an interesting study on the genetics of several species and populations in North Africa. This paper show many important results and will be an important basis for further studies into the taxonomy and the venom of the different taxa. See abstract for further details.

The genus Androctonus, commonly known as fat-tailed scorpions, contains 22 species distributed from Togo and Mauritania in the west, North Africa, through the Middle East and to as far east as India. With 13 species, a substantial amount of this genus’ diversity occurs in North Africa, which is a major hotspotof scorpion sting incidents. Androctonus are among the most medically relevant animals in North Africa.Since venom composition within species is known to vary regionally, the improvement of therapeutic management depends on a correct assessment of the existing regional specific and sub-specific variation. In this study, we assessed the phylogeographical patterns in six species of Androctonus scorpions from North Africa using mitochondrial DNA markers. We sequenced COX1, 12S, 16S and ND1 genes from110 individuals. Despite lacking basal resolution in the tree, we found taxonomical and geographically coherent clades. We discovered deep intraspecific variation in the widespread Androctonus amoreuxi and Androctonus australis, which consisted of several well-supported clades. Genetic distances between some of these clades are as high as those found between species. North African A. australis have a deep split in Tunisia around the Chott el-Djerid salt-lake. A novel split between A. amoreuxi scorpions was found in Morocco. We also found deep divergences in Androctonus mauritanicus, corresponding to areas attributed to invalidated subspecies. In addition we uncovered a clade of specimens from coastal south Morocco, which could not be ascribed to any know species using morphological characters. Based on these findings we recommend a reassessment of venom potency and anti-venom efficacy between these deep intraspecific divergent clades.

Coelho P, Sousa P, Harris DJ, van der Meijden A. Deep intraspecific divergences in the medically-relevant fat-tailed scorpions (Androctonus, Scorpiones). Acta Trop. 2014 Feb 10;134:43-51. [Subscritpion required for full text]

Thanks to Arie van der Meijden for sending me their article!

Family Buthidae

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