Buthus


Buthus is a genus of scorpion belonging and being eponymous to the family Buthidae. It is distributed widely across northern Africa, including Morocco, Mauritania, Algeria, Tunisia, Libya, Egypt, Senegal, Guinea-Bissau, Nigeria, Sudan, Somalia, Ethiopia, Djibouti, as well as the Middle East, including Israel, Palestine, Jordan, Lebanon, Iraq, Yemen, and possibly Saudi Arabia and southern Turkey. Its European range includes the Iberian Peninsula, southern France, and Cyprus.

Taxonomy

The genus was introduced by W.E. Leach. It was only the second genus of scorpion as all species known to this date were included in the sole genus Scorpio Linné, 1758. Leach found Scorpio occitanus Amoreux, 1789 to differ from the other species of Scorpio known to him by having eight eyes instead of six. C.L. Koch expanded this concept and subdivided the scorpions in four families according to the number of their eyes. He named his second family, the "eight-eyed scorpions", Buthides. The use of the number of eyes in the classification of scorpions has been discarded since, however the name Buthidae is still in use for the most diverse family of scorpions.

Diversity

The content of this genus may vary, depending on the authority. The best known species, B. occitanus, was once thought to be widespread from southern France, throughout Spain and Morocco, along the southern coast of the Mediterranean Sea, and eastwards as far as Israel. However, recent research has shown that it forms a highly diverse cluster of closely related but separate species. A number of taxa formerly considered as subspecies or "varieties" have been granted full species status, others have been described as entirely new. The Moroccan Atlas region is a hot-spot of diversity with at least 14 species. This diversity is explained by the topography which led to a high degree of speciation in populations which are separated from others by mountain ranges. Four species are considered to occur in Europe: B. occitanus, B. montanus, B. ibericus, and B. kunti. At least 75 species are known, many of which are quite similar in appearance:
Members of Buthus are generally medium-sized scorpions. Coloration is generally yellow, with different tones of brown to red-brown. Darker patterns may occur on various parts of the body. The pedipalps are relatively gracile with slender digits and a globose base. The cephalothorax bears strong ornamentation with small granules arranged to form carinae. The most prominent carinae form a lyra-shaped pattern behind the median eyes in many species. The mesosoma is also often granulated and commonly bears three ridges on the tergites. The metasoma is slender but not thin with well developed carinae of granules, and some short spines in some species. A large vesicle terminates in a sharp and long aculeus.

Toxicity

Though generally not considered lethal, the venom of Buthus species is considered of medical importance. They form a considerable part of scorpion envenomation cases, especially in northern Africa. According to a study by Touloun et al. scorpions of the B. occitanus complex caused 26% of all recorded cases in southwestern Morocco, but none of them resulted in death.

Habitat

Species of Buthus live in semi-arid to arid climate in various terrains, from mountain valleys to coastal plains mostly with sparse vegetation, even in deserts. As most scorpions they are predominantly nocturnal and hide in shallow burrows, most commonly below stones.