The evolution and distribution of noxious species of scorpions (Arachnida: Scorpiones)

Abstract

This contribution attempts to bring some general information on the evolution and, in particular, on the geographic distribution of scorpion species noxious to humans. Since 95% of the scorpions incidents are generated by specimens of the family Buthidae C. L. Koch, the analysis will be limited to this familial group. As in previous similar contributions, the content of this work is mostly addressed to non-specialists whose research embraces scorpions in several fields such as venom toxins and public health. Only in recent years, efforts have been made to create better links between ‘academic scorpion experts’ and other academic non-specialists who use scorpions in their research. Even if a larger progress can yet be expected from such exchanges, crossed information proved to be useful in most fields of scorpion studies. Since the taxonomy of scorpions is complex, misidentifications and even more serious errors concerning scorpion classification/identification are often present in the general literature. Consequently, a precise knowledge of the distribution patterns presented by many scorpion groups and, in particular, those of infamous species, proves to be a key point in the interpretation of final results, leading to a better treatment of the problems caused by infamous scorpion species.

Tick Paralysis: Solving an Enigma

“…The family Ixodidae is represented by 59 species, including eight from the genus Amblyomma , 10 from the genus Dermacentor , seven from the genus Haemaphysalis , three from the genus Hyalomma , 20 from the genus Ixodes , 10 from the genus Rhipicephalus , and one species of Rhipicentor [ 10 ]. Paralysis species, therefore, comprise less than 8% of all known tick species and this gives an interesting comparison to other arachnids that are considered to be venomous, such as spiders (~99% venomous from ~47,000 species) or scorpions (100% venomous from ~2300 species) [ 37 , 38 ]. Of these, only Argas walkerae (South Africa), I. holocyclus (Australia), Ixodes rubicundus (South Africa), Dermacentor andersoni , Dermacentor variabilis (North America), and Rhipicephalus evertsi evertsi (Africa), is considered as species that cause significant paralysis in host species [ 7 , 39 ], making the number of species for which frequent paralysis is observed, less than 1% of all tick species.…”

Scorpions and life-history strategies: from evolutionary dynamics toward the scorpionism problem

“…This basic model seems to be perfectly applicable to several infamous species of Tityus in South America, Centruroides in North America and Androctonus in North Africa [2–4]. …”

Journal of Venomous Animals and Toxins including Tropical Diseases

“…The structure was already present in Eurypterids and is yet common in several arthropod groups such as Xiphosura (horseshoe crabs). This posterior-most division of the body of an arthropod is not however considered as a true segment since it does not arises in the embryo from teloblast areas as do real segments [3].…”