All you need to know about scorpion weapons and their function

 

Scorpions are armed with two types of weapons: their pedipalps with powerful pincers and their stinger which can inject an effective venom. These weapons are essential for the scorpion's survival and have three main functions: Prey capture, defense and sexual behavior. 

Yuri Simone and Arie van der Meijden have recently published an very thorough and interesting review on all aspects of the scorpion weapons. Here you will find all you need to know about our current knowledge on the scorpion's use of their pincers, sting and venom, how they work and how the originated. This is probably the most complete overview I have ever read on this topic and I recommend the article very much! 

Abstract:
Scorpions possess two systems of weapons: the pincers (chelae) and the stinger (telson). These are placed on anatomically and developmentally well separated parts of the body, that is, the oral appendages and at the end of the body axis. The otherwise conserved body plan of scorpions varies most in the shape and relative dimensions of these two weapon systems, both across species and in some cases between the sexes. We review the literature on the ecological function of these two weapon systems in each of three contexts of usage: (i) predation, (ii) defense and (iii) sexual contests. In the latter context, we will also discuss their usage in mating. We first provide a comparative background for each of these contexts of usage by giving examples of other weapon systems from across the animal kingdom. Then, we discuss the pertinent aspects of the anatomy of the weapon systems, particularly those aspects relevant to their functioning in their ecological roles. The literature on the functioning and ecological role of both the chelae and the telson is discussed in detail, again organized by context of usage. Particular emphasis is given on the differences in morphology or usage between species or higher taxonomic groups, or between genders, as such cases are most insightful to understand the roles of each of the two distinct weapon systems of the scorpions and their evolutionary interactions. We aimed to synthesize the literature while minimizing conjecture, but also to point out gaps in the literature and potential future research opportunities.

Reference:
Simone Y, Meijden Avd. Armed stem to stinger: a review of the ecological roles of scorpion weapons. J Venom Anim Toxins Incl Trop Dis. 2021;27. [Open Access]

Thanks to Yuri Simone for informing me about their article!

New species of Ananteris from Brazil

 

Wilson Lourenco has recently described a new species of Ananteris Thorell, 1891 (Buthidae) from Brazil.

Ananteris martensi Lourenco, 2021

Abstract:
Some additional comments are proposed on the historical aspects of the subfamily Ananterinae (sensu Pocock 1900). The worldwide pattern of distribution of the elements associated with this subfamily is briefly discussed. The biogeographic patterns presented by extant and fossil elements of this subfamily confirm not only the characteristics of a group presenting a typical Gondwanian distribution, but may also correspond to older Pangaean patterns. One unexpected new species is described for the genus Ananteris Thorell from the State of Goiás in Central Brazil, Ananteris martensi sp. n., suggesting that the diversity levels of the Cerrados formations are most certainly higher than what is normally admitted.

Reference:
Lourenco WR. Some additional comments on the Ananteridae or 'Ananteris group' and description of a new species of Ananteris Thorell from Central Brazil (Scorpiones: Buthidae). Zootaxa. 2021;4984(1):347356. [Subscription required for full text]

Thanks to Jairo A. Moreno-González  for sending me this article!

Family Buthidae

Four new lithophilic species of Scorpiops from peninsular India

 

India has a large scorpion diversity, and much of it is probably not discovered yet. Shauri Sulakhe and co-workers have recently described four new species of Scorpiops Peters, 1861 (Scorpiopidae) from peninsular India. All species are lithophiles.

Scorpiops lioneli Sulakhe, Deshpande, Dandekar, Padhye & Bastawade, 2021

Scorpiops nagphani Sulakhe, Deshpande, Dandekar, Padhye & Bastawade, 2021

Scorpiops neera Sulakhe, Deshpande, Dandekar, Padhye & Bastawade, 2021

Scorpiops vrushchik Sulakhe, Deshpande, Dandekar, Padhye & Bastawade, 2021

Some of these species inhabit some truly beautiful habitats based on the pictures in the article. The article has an identification key for all species known from peninsular India.

Abstract:
Four new lithophilic species of Scorpiops Peters, 1861 (Scorpiopidae) have been described from peninsular India using an integrated taxonomic approach. Three species Scorpiops vrushchik sp. n., S. nagphani sp. n. and S. neera sp. n. have been described from northern Western Ghats and S. lioneli sp. n. is described from Deccan Plateau. S. vrushchik sp. n. is closely related to S. tenuicauda and S. telbaila and differs by a raw genetic divergence of 9.6-9.8% from S. tenuicauda and 11% from S. telbaila. S. nagphani sp. n. is closely related to S. lioneli sp. n. and S. maharashtraensis and differs by a raw genetic divergence of 6.7% from S. lioneli sp. n. and 9.6% from S. maharashtraensis. S. neera sp. n. is closely related to S. deccanensis, S. satarensis and S. phaltanensis and differs by a raw genetic divergence of 6.1–7.1% from S. deccanensis, 7.3% from S. satarensis and 9.6–9.8 % from S. phaltanensis. S. lioneli sp. n. is closely related to S. nagphani sp. n. and S. maharashtraensis and differs by a raw genetic divergence of 6.7% from S. nagphani sp. n. and 11% from S. maharashtraensis. Hemispermatophore morphology of all the new species is described with photographs. A taxonomic key to all species of Scorpiops from peninsular India is provided. This study elevates the number of species of Scorpiops found in India to 27, out of which 11 are found in peninsular India.

Reference:
Sulakhe S, Deshpande S, Dandekar N, Padhye A, Bastawade D. Four new lithophilic species of Scorpiops Peters, 1861 (Scorpiones: Scorpiopidae) from peninsular India. Euscorpius. 2021(337):1-49. [Open Access]

Family Scorpiopidae

A new medical significant Tityus species from Argentina

 

The genus Tityus C. L. Koch, 1836 (Buthidae) contains some of the most medical significant species in South America and in the world. One the the most infamous species is Tityus trivittatus Kraepelin 1898, a species known to cause death and serious morbidity in parts of Brazil, Paraguay, Uruguay and Argentina.

Andrés Alejandro Ojanguren Affilastro and co-workers have recently done a taxonomic and phylogenic study of Tityus trivittatus. Their study shows that the poplations of T. trivittatus in Argentia is acutally a separate species.

Tityus carrilloi Ojanguren Affilastro, 2021 (Argentina)

We know that the new species is medically significant because this has been documented for these populations previously (as Tityus trivittatus). The discovery of this new species is important, as the venom content of T. trivittatus and T. carrilloi vary and this may have consequences for the treatment of sting patients. 

This is an important study as knowledge about the taxonomy of venomous species is important both for treatment and prevention and control.

Abstract:
Tityus trivittatus is considered the most medically important scorpion species of southern South America. In this contribution we redefine its taxonomy, redescribe the species and separate the southern populations as a new species, Tityus carrilloi n. sp. As a consequence of this description, the most medically important species of the region turns out to be the new species herein described. We also clearly establish the phylogenetic position of both species through a dated molecular phylogenetic analysis based on four genes. Finally, we discuss the differences of the venom between the two species, and the epidemiologic implications of our results on the scorpionism problem in the region.

Reference:
Ojanguren A, Kochalka J, Orellana D, Garcete Barrett BR, Borges A, Ceccarelli F. Redefinition of the identity and phylogenetic position of Tityus trivittatus Kraepelin 1898, and description of Tityus carrilloi n. sp. (Scorpiones; Buthidae), the most medically important scorpion of southern South America. Revista del Museo Argentino de Ciencias Naturales, Nueva Serie. 2021;23:27-55. [Open Access]

Family Buthidae

Relationship between scorpion sting events and environmental conditions in mainland France

 

Jules-Antoine Vaucel and co-workers have published a thorough study of scorpion stings in mainland France. This is interesting in itself and I find it especially interesting that they report of one event of scorpion sting involving the enigmatic B. xambeui Simon, 1879 (Belisaiidae). Unfortunately, they present no details on this incident, but I guess it caused no serious morbidity. Other species represented in the study were Buthus occitanus (Amoreux, 1789) (Buthidae) and Euscorpius concinnus (Koch, 1837), Euscorpius italicus (Herbst, 1800), Euscorpius tergestinus (Koch, 1837), and Tetratrichobothrius flavicaudis (De Geer, 1778) (all in the family Euscorpiidae).

As the title indicate, the authors have tried to find a relationship relationship between scorpion sting events and environmental conditions like level of sunshine, temperature etc. The authors conclude that climatic variations could well predict encounters between humans and scorpions in France. 

Abstract:
In the world, the impact of environmental conditions on the number of scorpion events was evaluated in North Africa,Middle East, and the Amazonian region but not in Europe. In mainland France, scorpion species described are Buthus occitanus (Amoreux, 1789), Belisarius xambeui (Simon, 1879) and 4 Euscorpiidae: Euscorpius concinnus (Koch, 1837), Euscorpius italicus (Herbst, 1800), Euscorpius tergestinus (Koch, 1837), and Tetratrichobothrius flavicaudis (De Geer, 1778). We aimed to describe the impact of environmental conduction on the number of scorpion events. For this, a retrospective multi-center study was conducted with data from the French poison control centers files about scorpion events between 1 January 2011 and 31 December 2020. During the study period, 975 incoming calls for scorpion events were recorded and 574 were related to scorpions native to mainland France and Corsica: B. occitanus (n = 86), Euscorpiidae species (n = 222), B. xambeui (n = 1), and undetermined species (n = 265). Cases were mostly reported along the Mediterranean coast, along rivers, and in cities with a trading port. The number of scorpion events was linked to the rivers' water level, rivers' flow, temperature, sunshine, and pluviometry (P < 0.05 for all variables). B. occitanus need warmest and driest environment than Euscorpiidae spp. A link between the severity of the envenoming and climatic condition or seasonality was not demonstrated.

Reference:
Vaucel JA, Larreche S, Paradis C, Labadie M, Courtois A, Grenet G, et al. Relationship Between Scorpion Stings Events and Environmental Conditions in Mainland France. J Med Entomol. 2021. [Subscription required for full text]

Yet another species of Buthus from Algeria

 

Haroun Abidi and co-workers have described a new species of Buthus Leach, 1815 (Buthidae) from the coastal region of El-Tarf, in the north-eastern range of Algeria.

Buthus goyffoni Abidi, Sadine & Lourenco, 2021

A revised diagnosis of Buthus paris (C. L. Koch, 1839) is also given.

Abstract:
One more new species of Buthus is described from the coastal region of El-Tarf, in the north-eastern range of Algeria. This new species may represent a possible vicariant element of Buthus paris (C. L. Koch, 1839), a species equally known from the north of Algeria, but inhabiting much higher altitudes in the coastal massifs. The number of confirmed species of Buthus in Algeria is raised to nine.

Reference:
Abidi H, Sadine SE, Houhamdi M, Madoui A, Lourenco WR. The genus Buthus Leach, 1815 in Algeria (Scorpiones: Buthidae) and a possible new case of vicariant species. Revista Iberica de Arachnologia. 2021(38):81-6.

Thanks to Dr. Sadine for sending me their article!

Family Buthidae

A phylographic study of the widespread, southern devil scorpions Vaejovis carolinianus in the USA

 

Several studies have revealed cryptic spices within the genus Vaejovis C.L. Koch, 1836 (Vaejovidae) in the southeastern USA. With this in mind, Matthew Graham and co-workers have conducted a thorough phylographic analysis of the more widespread species Vaejovis carolinianus (Beauvois, 1805). 

The authors expected to find cryptic species in some of the different populations of this species, but the genetic analysis did not support this. Even though several genetical clades were identified, all populations are the same species. 

Check out the article to learn more about the phylography of Vaejovis carolinianus. 

Abstract:
The Southern Appalachians and adjacent provinces of the southeastern USA are geologically and biologically diverse, with high levels of endemism. Phylogeographic analyses indicate that animals with small distributions in these regions often contain cryptic diversity and that Pleistocene climate fluctuations had significant impacts on their distributions. We studied the phylogeography of Vaejovis carolinianus (Beauvois), a common forest scorpion from the region, to determine if a more widely distributed animal exhibits similar patterns. Mitochondrial and nuclear DNA, as well as species distribution models, were used to test biogeographic hypotheses. Results indicate that the species is composed of at least nine geographically structured mitochondrial clades. Seven clades are represented by only a few sampling locations, whereas two clades are much larger and appear to be the result of postglacial range expansion in the plateaus and coastal plains adjacent to the Southern Appalachians. A highly disjunct population from Tunica Hills of Louisiana appears to have been isolated since the Pliocene, rejecting a hypothesis of late glacial migration along the Blufflands escarpment. Nuclear DNA is much less structured, perhaps due to differences in habitat and dispersal capabilities between sexes. Although mitochondrial lineages are quite old, mito-nuclear discordance suggests that lineages have not sorted and that V. carolinianus should be treated as a single genetically diverse species.

Reference:
Graham MR, Garcia EL, Hendrixson BE, Sampognaro AM, Cushing PE. Pliocene origins, Pleistocene refugia, and postglacial range expansions in southern devil scorpions (Vaejovidae: Vaejovis carolinianus). Organisms Diversity & Evolution. 2021;Published online 31. July 2021. [Subscription required for full text]

Family Vaejovidae