Although the use of DNA barcoding to identify species has been a highly contentious issue among biologists (for reasons I will not get into here), there is no doubt that the practice has led to valuable contributions to our understanding of the world’s biodiversity. In a manuscript that was recently accepted for publication, Victor Fet, myself, and international collaborators Pavel Stoev (Bulgaria), Nesrine Akkari (Denmark), and Gergin Blagoev (Canada) provide yet another example of how DNA barcodes can be used for more than just identifying species. Using DNA barcodes from Euscorpius species collected throughout the Mediterranean, we were able to investigate the controversial natural occurrence of Euscorpius sicanus (C.L. Koch) in North Africa (Tunisia).
In brief, our results suggest that North African E. sicanus, as predicted by Fet et al. (2003), most likely represent an isolated relict population and not a recent introduction to the region. Excitingly, molecular clock estimates suggest that E. sicanus in North Africa have been isolated since the Zanclean Flood, a sudden refilling of the Mediterranean Sea after it had evaporated during the Messinian salinity crisis. The Zanclean Flood is thought to have filled the Mediterranean in 2 months to 2 years, which is incredibly rapid in terms of geologic time, so we propose that the flood could potentially be used as an incredibly precise geologic calibration for fine-tuning molecular clocks in the Mediterranean.Our manuscript is slated for publication in the next issue of Serket, the Arachnological Bulletin of the Middle East and North Africa. Thank you to Jan Ove Rein of The Scorpion Files for permission to use his digital version of Koch’s stunning painting of E. sicanus from the 1830s.
Fet, V., Soleglad, M.E., Gantenbein, B., Vignoli, V., Salomone, N., Fet, E.V. & Schembri, P.J. 2003. New molecular and morphological data on the “Euscorpius carpathicus” species complex (Scorpiones: Euscorpiidae) from Italy, Malta, and Greece justify the elevation of E. c. sicanus (C. L. Koch, 1837) to the species level. Revue suisse de Zoologie, 110(2): 355–379.
Graham, M.R., P. Stoev, N. Akkari, G. Blagoev & V. Fet. (in press) Euscorpius sicanus (Scorpiones: Euscorpiidae) from Tunisia: DNA barcoding confirms ancient disjunctions across the Mediterranean Sea. Serket.