03 June, 2015

A new study elevates several Scorpio maurus subspecies in Palestina and Israel to species status

Scorpio maurus Linneaus, 1758 (Scorpionidae) has been considered monotypic (one species) for almost a century, having at the most 19 recognized subspecies. In spite of a wide distribution in Africa and Asia and occurrence in different habitats, is has been very difficult to find taxonomical characteristics proving that Scorpio maurus in reality is a species complex with many hidden species. The opinion for many years has been that Scorpio maurus is a single, widespread, polymorphic species.

In 2009, Lourenco elevated several subspecies in North Africa to species status. Since them, other species have been described (Blog posts on Scorpio). Talal and co-workers have now published a very interesting study of the Scorpio maurus populations in Palestina and Israel, focusing especially on the two subspecies Scorpio maurus fuscus Ehrenberg, 1829 and Scorpio maurus palmatus Ehrenberg, 1829. The study revealed seven geographically-delimited clades of Scorpio maurus, corresponding to at least four currently recognized subspecies in their study area. Based on genetic, morphological and behavioral support, the authors elevate four subspecies to species status. The results presented support the theory that Scorpio maurus in reality is a species complex, comprising of multiple distinct phylogenetic, ecological and biological species.

Scorpio fuscus (Ehrenberg, 1829). Previously Scorpio maurus fuscus Ehrenberg, 1829.
Scorpio kruglovi (Ehrenberg, 1829). Previously Scorpio maurus kruglovi Ehrenberg, 1829.
Scorpio palmatus (Ehrenberg, 1829). Previously Scorpio maurus palmatus Ehrenberg, 1829.
Scorpio propinquus (Simon, 1872). Previously Scorpio maurus propinquus Simon, 1872.

 Check the article for information about the distribution of the new species.

Scorpio Linnaeus, 1758 (family Scorpionidae Latreille, 1802) was considered monotypic for over a century, and comprised a single species, Scorpio maurus Linnaeus, 1758, with 19 subspecies, distributed fromWest Africa, throughout the Maghreb and the Middle East, to Iran. Two parapatric subspecies, Scorpio maurus fuscus (Ehrenberg, 1829) and Scorpio maurus palmatus (Ehrenberg, 1828), have long been recognized in Israel.We examined morphological variation, burrow architecture and genetic divergence among 39 populations across the distribution of the two subspecies to assess whether they are conspecific and, if not, how many species might be involved. Cuticle coloration, pedipalp chela digital carina condition, and selectedmeasurements were recorded. Sixty burrows were excavated and examined for burrow structure and depth. A multilocus dataset comprising concatenated fragments of one nuclear (28S rDNA) and three mitochondrial (12S rDNA, 16S rDNA, Cytochrome c Oxidase Subunit I) loci, totaling ca. 2400 base-pairs, was produced for individuals, and a single-locus dataset comprising 658 base-pairs of the COI locus for 156 individuals. Despite overlapping ranges in morphometric characters of pedipalp chela shape, the putative subspecies were easily distinguished by cuticle coloration and condition of the pedipalp chela digital carina, and were also found to differ significantly in burrow architecture and depth. Phylogeographical analyses of the COI and multilocus datasets recovered seven distinct clades. Separate analyses of mitochondrial sequences, and combined analyses of mitochondrial and nuclear sequences support most clades. The two major clades corresponded with the geographical distributions of S. m. fuscus and S. m. palmatus in the region. Specimens from these clades were genetically distinct, and exhibited different burrow structure in geographically-proximate localities, suggesting reproductive isolation. The palmatus clade included two distinct subclades of specimens from localities adjacent to the Dead Sea. Three other clades, comprising specimens from the most northeastern localities, were tentatively assigned to subspecies previously recorded in neighboring Jordan and Syria. The morphological, behavioral and genetic evidence supports previous suggestions that Scorpio maurus is a species complex and justifies the following taxonomic emendations: Scorpio fuscus (Ehrenberg, 1829), stat. nov.; Scorpio kruglovi (Ehrenberg, 1829), stat. nov.; Scorpio palmatus (Ehrenberg, 1828), stat. nov.; Scorpio propinquus (Simon, 1872), stat. nov.

Talal S, Tesler I, Sivan J, Ben-Shlomo R, Muhammad Tahir H, Prendini L, et al. Scorpion speciation in the Holy Land: Multilocus phylogeography corroborates diagnostic differences in morphology and burrowing behavior among Scorpio subspecies and justifies recognition as phylogenetic, ecological and biological species. Mol Phylogenet Evol. 2015 May 15.[Subscription required for full text]

Family Scorpionidae

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