28 February, 2013

Scorpion envenomation in children in the United States

Skolnik and Ewald have recently published a review on scorpion stings involving children in USA. The only potential dangerous species in USA is Centruroides sculpturatus Ewing, 1928 (Buthidae). Even though only one deaths has been reported in the literature since 1970 (and this was probably an allergic reaction), there is no doubt that C. sculpturatus may cause serious morbidity in children. The current paper is important in summing up current knowledge and treatment of scorpion envenomations in USA.

In the Southwestern United States, the venom of the scorpion Centruroides sculpturatus (common name bark scorpion) can cause serious and potentially fatal neurotoxicity, with young children most vulnerable to its effects. Historically, advances in the quality of supportive care have made significant improvements in morbidity and mortality. In recent years, the development of effective antivenom therapies has changed the landscape of caring for these patients. This article reviews the background, pathophysiology, diagnosis, and treatment options for C. sculpturatus envenomation. Recent advances in immunotherapy and subsequent implications for pediatric emergency care providers are discussed.

Skolnik AB, Ewald MB. Pediatric scorpion envenomation in the united states: Morbidity, mortality, and therapeutic innovations. Pediatr Emerg Care. 2013 January 2013;29(1):98-103. [subscription required for full text]

25 February, 2013

What do we mean when we talk about scorpion distribution?

Michael Warburg has recently published an article discussing what is actually meant by distribution. Does one mean geographical distribution or local distribution? Warburg introduces the terms mini-distribution, micro-distribution and macro-distribution and relates different distributional data from five species in northern Israel to these terms.

Scorpions being solitary animals are interesting in their distribution patterns. Nevertheless, the subject ofscorpion distribution has received relatively less attention than other ecological aspects of that group. It is amatter that changes continuously and moreover it is hard to define. Three different scales in distribution areintroduced here: (1) Mini- distribution which describes the presence of scorpions under a single shelter or in aburrow, within a single habitat, (2) micro-distribution describing the distribution within a single habitat, and (3) macro-distribution within different habitats. Most research in scorpion distribution concentrated on the first aspect the mini-distribution. The subject is reviewed in scorpions and discussed.

Warburg MR. Scaling distribution in scorpions. Arthropods. 2013;2(1):7-19. [Free full text]

Thanks to Gerard Dupre for sending me this article!

20 February, 2013

Ecological niche modeling of two buthids from Iran

Imid Mirshamsi has recently published a study on ecological niche modeling of the two species Mesobuthus eupeus (C. L. Koch, 1839) and M. phillipsii (Pocock, 1889) (Buthidae) from Iran.

This type of study is important for understanding taxonomy, species distribution and species evolution.

Ecological niche modeling has allowed several advances in the process of species delimitation. In the present study, I used this method to evaluate the climatic divergence between two scorpion species, Mesobuthus eupeus and M. phillipsii. The ecological niche models (ENMs) were created based on presence-only data with the maximum entropy method. The created models, results of spatial analysis (PCA and Hotelling discriminant), and an identity test suggested that the divergence between these two species is associated with significant divergence in their ecological niches. The results of this study provide additional support for the taxonomic validity the studied species.

Mirshamsi O. Ecological niche modeling of two scorpion species Mesobuthus eupeus (C. L. Koch, 1839) and M. phillipsii (Pocock, 1889) from the Iranian Plateau and Zagros region (Arachnida: Scorpiones). Euscorpius. 2012 (154):1-10. [Free full text]

19 February, 2013

A new Vaejovis from Arizona mountains, USA

Vaejovis brysoni Ayrey & Webber, 2013 (Photo: Richard Ayrey)

 Richard Ayrey and Michael Webber have described another new species of Vaejovis C. L. Koch, 1836 (Vaejovidae) from the Santa Catalina Mountains in Arizona, USA.

Vaejovis brysoni Ayrey & Webber, 2013

A new species of the vorhiesi group of Vaejovis C.L. Koch, 1836, Vaejovis brysoni sp. n., is described from the Santa Catalina Mountains in southern Arizona. Vaejovis deboerae Ayrey also inhabits this mountain range, making this the first documented case of two vorhiesi group species distributed on the same mountain. When compared to all other vorhiesi group species, Vaejovis brysoni sp. n. is distinct based on several combinations of morphological characters and morphometric ratios.

Ayrey RF, Webber MM. A new Vaejovis C.L. Koch, 1836, the second known vorhiesi group species from the Santa Catalina Mountains of Arizona (Scorpiones, Vaejovidae). ZooKeys. 2013 (270):21-35. [Free full text]

Thanks to Richard Ayrey for informing me about the paper and for sharing a picture of the new species with The Scorpion Files!

Family Vaejovidae

18 February, 2013

Two new species of Diplocentrus from Guatemala

Rony Trujillo and Luis de Armas have recently published two new species of Diplocentrus Peters, 1861 (Scorpionidae) from Guatemala.

Diplocentrus landelinoi Trujilo & Armas, 2012
Diplocentrus oxlajujbaktun Trujilo & Armas, 2012

Two new species of the genus Diplocentrus Peters, 1861 are described on the basis of three female specimens from the departments of Petén and Izabal, Guatemala. The species from Izabal resembles D. lourencoi Stockwell, 1988, from the same range (Cordillera del Merendón) but in Honduran territory. The species from Petén resembles D. maya Francke, 1977, recorded from Belize (Toledo District) and north-eastern Guatemala (departments of Petén and Izabal).

Trujillo RE, de Armas LF. Dos especie nuevas de Diplocentrus Peters, 1861 (Scorpionidae: Diplocentrinae) de Guatemala. Revista Iberica de Arachnologia. 2012 (21):131-8.

Family Diplocentridae

11 February, 2013

A updated review on the treatment of scorpion envenomations

Jean-Philippe Chippaux has recently published an updated review on the options for treating scorpion envenomations. On average 1.5 million envenomations happen worldwide every year, causing 2600 deaths. Updated information about the treatment of scorpin stings is therefore very important.

The objective of this review is to update knowledge on the management of scorpion stings and treatment of scorpion envenomings, to discuss the advantages and limitations of early immunotherapy versus medical resuscitation, and to offer a standardized management plan based on a combination of both strategies.

Scorpion stings are common in many tropical countries. Although most scorpion stings cause only localized pain without life-threatening envenoming, about one third of stings cause systemic envenoming which can result in death. Children are particularly sensitive to scorpion envenoming. The severity of scorpion stings is related to the presence of neurotoxins in the venom that cause a sudden release of neurotransmitters from the autonomic nervous system, predominantly sympathetic. There is also a strong inflammatory response that worsens symptoms, including those of a respiratory nature. Several vital functions may be directly affected, including the cardiovascular, respiratory, and neuromuscular systems. Hypertension is constant at the beginning of systemic envenoming and sometimes has a severe cardiac and respiratory impact. Although controversial, immunotherapy is the only etiological treatment. Administered early, it prevents many complications and improves the outcome. New antivenoms are highly purified immunoglobulin fragments, the efficacy and safety of which are excellent. As a consequence, adverse reactions to antivenoms are now very rare and usually mild, which should limit any reluctance regarding their routine use. Symptomatic treatment is still necessary to support immunotherapy, especially in cases of delayed arrival at hospital. A combination of both approaches should be considered, based on local resources and constraints.

Chippaux JP. Emerging options for the management of scorpion stings. Drug Des Devel Ther. 2012 03 Jul;6:165-73. [Free full text]

07 February, 2013

Scorpions found in the Hainan Island, China

Zhi-Young Di and several co-workers have published a paper about the scorpion fauna of the Chinese island of Hainan. An identification key for the species on the island is provided:

The redescriptions and illustrations of three species, Isometrus (Isometrus) maculatus (DeGeer, 1778), Lychas mucronatus (Fabricius, 1798) (Buthidae), and Liocheles australasiae (Fabricius, 1775) (Hemiscorpiidae) from Hainan Island, China are presented. Distribution data and updated key of Hainan scorpions are provided.

Di Z-Y, Cao Z-J, Wu Y-L, Zhu L, Liu H, Li W-X. The scorpions of Hainan Island, China (Arachnida: Scorpiones). Euscorpius. 2013 (153):1-22. [Free full text]

05 February, 2013

A review on plants used to treat scorpion stings

Gerard Dupre has recently published a review article summing up the knowledge about the use of plants in the treatment of scorpion envenomations around the world. Dupre lists no less than 721 different plant species that are in use or have been used for scorpion stings. India tops the list with 266 species.

I will not start a discussion here about the effects of plants on scorpion stings. It is important to seek medical attention in serious envenomation cases (if possible). I will not rule out, though, that some of these plants probably have more or less effects on some or all symptoms from a scorpion sting. Many drugs have their origin from traditional medicine and it is possible that a potential valuable treatment for scorpion sting may be hidden within one of the plant species listed in Dupre's paper.

Until today the treatment of scorpion stings by means of plants occupies a significant place in traditional medicine, and in spite the emergence of modern medicine, people have kept on using plants, as the knowledge of which has been passed over centuries from one generation to the next as Ayurvedic medicine shows.

Dupre G. New synthesis on plants used to treat scorpion stings. American Journal of Pharmtech Research. 2013;3(1):175-225. [Free full text, but you have to browse down to article number 14]

Thanks to Gerard Dupre for sending me his paper!

04 February, 2013

A review on Hottentotta in Iran

Shahrokh Navidpour has recently published a review on the species of Hottentotta Birula, 1908 occurring in Iran. Seven species is so far reported from this country and an identification key for the species is provided.

Hottentotta is one of the most widely distributed genera of the family Buthidae, with species present throughout Africa, the Arabian Peninsula, and in Asia to Pakistan and India. Recently, Kovarik (2007) revised genus of Hottentotta in the world and reported 29 different species-group name in the genus of Hottentotta. Hottentotta is one of the six medical important scorpions of Iran that distributed in almost all parts of country. So, in this article morphological and morphometrical characters of six species of Hottentotta for better distinguishing have been described.

Navidpour S. A review study on Hottentotta Birula, 1908, (Scorpionida:Buthidae) species collected from Iran. Archives of Razi Institute. 2012;67(2):93-100. [Free full text]

Thanks to Gerard Dupre for sending me this paper!

A new species of Euscorpius from Corfu, Greece

The number of scorpion species in Europe is still growing. Many scorpion populations, especially in Greece and on the Balkans, await investigations. This time Tropea and Rossi have described a new species of Euscorpius Thorell, 1876 (Euscorpiidae) from the island of Corfu in Greece.

Euscorpius corcyraeus Tropea & Rossi, 2012

Euscorpius (Euscorpius) corcyraeus sp. n. is described based on specimens from Corfu Island, in Greece. It is characterized by small size, light colour and a typical mesotrichous trichobothrial pattern (Pv= 9, et= 6, em= 9, eb= 4).

Tropea G, Rossi A. A new species of Euscorpius Thorell, 1876 from Corfu, with notes on the subgenus Euscorpius in Greece. Onychium. 2012;9 (2011-2012):27-37.

Thanks to Gioele Tropea for sending me the article!

01 February, 2013

Phylogeography of the Arizona Hairy Scorpion (Hadrurus arizonensis)

Matthew Graham and co-workers have recently published an interesting and extensive article on the phylogeography of the Arizona Hairy Scorpion (Hadrurus arizonensis Ewing, 1928 - family Caraboctonidae). Phylogeography is the study of the historical processes that may be responsible for the contemporary geographic distributions of individuals (Wikipedia).

The authors conclude that mitochondrial sequence data suggest that the phylogeography of H. arizonensis was shaped by a history of fragmentation, reduced gene flow and demographic expansion since the late Pliocene. See abstract below for more details.

Aim As data accumulate, a multi-taxon biogeographical synthesis of the Mojave Desert is beginning to emerge. The initial synthesis, which we call the ‘Mojave Assembly Model’, was predominantly based on comparisons of phylogeographical patterns from vertebrate taxa. We tested the predictions of this model by examining the phylogeographical history of Hadrurus arizonensis, a large scorpion from the Mojave and Sonoran deserts.
Location Mojave and Sonoran deserts, United States and Mexico.
Methods We sequenced mitochondrial cytochrome c oxidase subunit I (COI) data from 256 samples collected throughout the range of H. arizonensis. We analysed sequence data using a network analysis, spatial analysis of molecular variance (SAMOVA), and a Mantel test. We then used a molecular clock to place the genetic patterns in a temporal framework. We tested for signals of expansion using neutrality tests, mismatch distributions and Bayesian skyline plots. We used Maxent to develop current and late-glacial species distribution models from occurrence records and bioclimatic variables.
Results Phylogenetic and structure analyses split the maternal genealogy basally into a southern clade along the coast of Sonora and a northern clade that includes six lineages distributed in the Mojave Desert and northern Sonoran Desert. Molecular dating suggested that the main clades diverged between the late Pliocene and early Pleistocene, whereas subsequent divergences between lineages occurred in the middle and late Pleistocene. Species distribution models predicted that the distribution of suitable climate was reduced and fragmented during the Last Glacial Maximum.
Main conclusions Genetic analyses and species distribution modelling suggest that the genetic diversity within H. arizonensis was predominantly structured by Pleistocene climate cycles. These results are generally consistent with the predictions of Pleistocene refugia for arid-adapted taxa described in the Mojave Assembly Model, but suggest that a northern area of the Lower Colorado River Valley may have acted as an additional refugium during Pleistocene glacial cycles.

Graham MR, Jaeger JR, Prendini L, Riddle BR. Phylogeography of the Arizona hairy scorpion (Hadrurus arizonensis) supports a model of biotic assembly in the Mojave Desert and adds a new Pleistocene refugium. Journal of Biogeography. 2013. Epub 30 Jan 2013. [Full text required for full text]

Thanks to Matthew Graham for sending me his paper!