Tityus pachyurus sting in Colombia - a case report

The genus Tityus C. L. Koch, 1836 is the most medical genus in South America and several species are known to cause death and serious morbidity, especially in children. In Colombia, Tityus pachyurus Pocock, 1897 is known to cause life threatening symptoms in children. This species pose a special threat because its normal habitat is inside and outside homes in some areas. 

Ledys Izquierdo & Javier Buitrago have recently published a paper presenting a case where a 12 year old boy was stung during sleep in his home. The boy developed serious symptoms, but survived after medical treatment.

Abstract:
The scorpion envenomation is considered the second event by poisonous animals in importance around the world according to the World Health Organization. In Colombia there are 35 species of clinical significance, among them, the genus Tityus, which contains the most deadly scorpions in South America and is represented by 29 species of wide distribution in Colombia, which include Tityus pachyurus causing life-threatening events, especially in children. The present work shows the case of a 12 years old boy, from Tolemaida to 2 h of Bogotá D.C., who was stung by a scorpion on his right thigh, with the onset of intense signs and symptoms of local effect rapidly progressing to severe systemic involvement causing myocardial dysfunction, cardiovascular collapse and heart arrest, and his favorable response to adequate basic and advanced life support and use of scorpionspecific F(ab0)2 antivenom.

Reference:
Izquierdo LM, Rodriguez Buitrago JR. Cardiovascular dysfunction and pulmonary edema secondary to severe envenoming by Tityus pachyurus sting. Case report. Toxicon. 2012. Epub 2012/06/12. [Subscription required for full text]

Burrows and burrowing in Hadrurus arizonensis

Daniel Hembree and co-workers have recently published a paper describing the forms and shapes of Hadrurus arizonensis Ewing, 1928 (Caraboctonidae) burrows. The authors are geologists (and/or palaentologists), and the angle and terminology of this papers is somewhat different from what I'm used to from the traditional scorpion literature. I must admit there are quite a few terms in the paper that unknown to me (but praise Google for being a helpful friend ;)

The goal of the paper is both to learn more about scorpion burrows, but also to aid in the recognition of scorpion burrows in the fossil record and to determine if aspects of palaeoenvironment can be ascertained by variations in scorpion burrow morphology.

The paper also has a nice mini-review of scorpion burrowing behavior and several pictures of burrow castings showing the form and shape of Hadrurus burrows.

Abstract:
Bioturbation by terrestrial animals is common in arid and semi-arid continental environments. Scorpions have comprised a significant portion of the diversity of predatory arthropods in these environments from the Late Paleozoic to the Recent. Many scorpions are active burrowers and likely have a substantial, if rarely recognized, ichnofossil record. This project involved the study of the burrowing behaviors and trace morphologies of the scorpion Hadrurus arizonensis (Scorpiones: Caraboctonidae). Individual animals were placed into sediment-filled terrariums for two- to three-week periods after which burrows were cast, excavated, and described. Descriptions of the subsurface structures included architecture, dimensions, bioglyphs, complexity, and tortuosity. Additional experiments were run with differing sediment composition, density, and moisture to evaluate the animal’s behavioral response to altering environmental conditions. Specimens of H. arizonensis burrowed by scratching and kicking loose sediment from the subsurface with the first two to three pairs of walking legs. The subsurface biogenic structures produced consisted of subvertical ramps, U-shaped burrows, helical burrows, and mazeworks. In the process of excavating the burrows, the desert scorpions also produced a hummocky surface topography as well as structures in dry, sandy sediment that resembled lamination and ripple cross-lamination. Increasing clay content and sediment density increased the complexity of burrow architectures produced. Reducing these variables limited the complexity of the burrows, reduced their likelihood of preservation, and increased the abundance of biogenic cross-lamination. Data collected from these and similar experimental studies can be applied to terrestrial ichnofossil assemblages in order to better interpret the paleoecology of ancient soil ecosystems.

Reference:
Hembree DI, Johnson LM, Tenwalde RW. Neoichnology of the desert scorpion Hadrurus arizonensis: burrows to biogenic cross lamination. Palaeontologia Electronica. 2012;15(1):1-34. [ Free full text]

Thanks to Jahn Hornung for informing me about this paper!

Clinical course of Centruroides sculpturatus envenomations managed without antivenom

In 2004, most supplies of the antivenom used to treat serious cases of Centruroides sculpturatus sting in the southwestern USA was exhausted, and supportive care and interventions became the only option available. Ayrn O'Connor and Anne-Michelle Ruha have now published a study showing the clinical course of Bark scorpion envenomations managed without antivenom.

The results show that treatment without antivenom are effective without antivenom, but 24 % of 88 patients (mainly children between 2 and 9 years) experienced respiratory failure and needed intubation. No mortality occurred, but this study show that C. sculpturatus is a dangerous scorpion for young children (and not only infants and toddlers).

In August 2011, a new antivenom for Centruroides was approved by FDA after studies showing it being effective in the treatment for serious cases. Unfortunately, this treatment is very expensive, and may force doctors and/or patients to limit the use. O'Connor & Ruha therefor highlight the importance of supportive treatment of severe scorpions stings.

Abstract:
Bark scorpion envenomation is potentially life threatening in children and traditionally treated with antivenom (AV). We sought to describe the clinical course, management, complications and outcome of children with severe scorpion envenomation treated with supportive care during a period when AV was unavailable. A retrospective chart review was performed, all children presenting to a referral hospital between September 1, 2004 and July 31, 2006 with severe scorpion envenomation not receiving AV, were included. A standardized data abstraction form was used to record time of symptom onset, time to healthcare facility (HCF), clinical findings, treatment, complications, and length of stay. Eighty-eight patients were included with mean age of 3.7 years (0.33–12). Mean time to symptom onset was 20 min (0–130) and mean time to HCF was 79 min (10–240). Incidence of clinical manifestations include: neuromuscular agitation, 100 %; opsoclonus, 97 %; hypersalivation, 81 %; tachycardia, 82 %; hypertension, 49 %; vomiting, 38 %; fever, 28 %; respiratory distress, 33 %; and hypoxia, 18 %. Complications included rhabdomyolysis in 18 (20 %) and aspiration in 12 (13 %) patients. Intubation was required in 24 % of patients. The most frequently used agents to control symptoms were benzodiazepines (98 %) followed by opioids (69 %). Intravenous fluids were given to 84 %. Mean length of stay was 29 h (range, 6–73 h). There were no deaths. In addition to the classic findings of neuromuscular hyperactivity, opsoclonus, and hypersalivation, a high incidence of hyperadrenergic findings and respiratory compromise are noted in this series. A significant number of patients required mechanical ventilation. Benzodiazpines and opioids were the most common medications used to control symptoms.

Reference:
O'Connor A, Ruha AM. Clinical Course of Bark Scorpion Envenomation Managed Without Antivenom. Journal of Medical Toxicology. 2012. Epub 2012/05/09. [Subscription required for full text]

More on Buthus phylogeny: Buthus elmoutaouakili in Morocco

My last blog post was about the situation for Buthus phylogeny and taxonomy. Today I learned about another contribution to the knowledge of Buthus in Northern Africa from Martin Husemann and co-workers.

Abstract:
When low dispersal ability of an organism meets geographical barriers, the evolution of inter- and intraspecific differentiation is often facilitated. In the Atlas massif of North Africa, the genus Buthus splits into several species and diverges into numerous genetic lineages, often following the orographic structures of mountain systems. Such high mountain ranges often act as barriers for species with reduced mobility even on small spatial scales. To study the effect of orographic structures on organisms with low dispersal ability, we collected 61 individuals of the scorpion species Buthus elmoutaouakili at 18 locations around the southwestern foothills of the High Atlas and Antiatlas and in the Sousse valley (western Morocco). We analyzed intraspecific differentiation patterns within this geographically restricted area of about 100 x 50 km using 452 bp of the cytochrome oxidase I mitochondrial gene. We detected 5 distinct genetic lineages. In a second analysis, we added 61 previously published sequences from Buthus species from Europe and North Africa. Using a molecular clock approach, we detected old splits (4–5 Ma) separating the samples from 1) the western High Atlas and north of these mountains, 2) the Sousse valley and adjoining mountain areas, and 3) the southwestern Antiatlas. Further differentiation happened in the first 2 geographical groups about 3 Ma. Thus, the divergence time estimates based on a Bayesian approach support the onset of differentiation into these main clades along the Pliocene (5–2.3 Ma) when climatic oscillations started and a constant global cooling preceded the glacial–interglacial cycles of the Pleistocene. Further genetic splits into parapatric groups are detectable for the Sousse valley main group in the early Pleistocene. The climatic oscillations of the Pliocene and early Pleistocene might have caused repeated range shifts, expansions, and retractions leading to repeated vicariance, hereby producing the hierarchical structure of genetic differentiation in B. elmoutaouakili. A taxonomic revision, including morphological and molecular data, is needed to assess the status of each of these Buthus scorpion lineages.

Reference:
Husemann M, Schmitt T, Stathi I, Habel JC. Evolution and Radiation in the Scorpion Buthus elmoutaouakili Lourenço and Qi 2006 (Scorpiones: Buthidae) at the Foothills of the Atlas Mountains (North Africa). J Hered. 2012;103(2):221-9. [Subscription required for full text]

Thanks to professor Wilson Lourenco for informing me about this article!

Family Buthidae

Phylogeographic patterns of Buthus from Europe and Northern Africa

In the last decade several new species of Buthus Leach, 1815 have been described from southern Europe and North Africa. In spite of this, the morphological identification of the Buthus species is still very difficult, mainly because of many descriptions and the few keys available use ambiguous and difficult characters.

Sousa and co-workers have recently published a very interesting paper that is the first step in the process of understanding the taxonomy and phylogeny of the genus Buthus.

Abstract:
The genus Buthus is a medium diverse scorpion genus, with 35 species distributed from Portugal and Morocco ranging eastward to Yemen in the Arabic Peninsula. The bulk of the genus’ known species diversity occurs in the Western Mediterranean area. A recent molecular study started to elucidate the patterns of diversity of this genus in the Iberian Peninsula and the Maghreb. Since then, the taxonomy of the genus has changed substantially, with several new species having been described, and with the elevation of former subspecies to species-level. In this study, we assessed the patterns of diversity of Buthus scorpions from across the Maghreb region of North Africa using CO1 DNA sequence data. Based on our dataset of 147 sequences, including 67 new sequences, we recovered four wellsupported deep clades within Buthus scorpions from the Maghreb and Southern Europe. This further strengthens the support for cryptic diversity in the Maghreb region. The broader sampling of the Maghreb permitted a better understanding of the phylogeographic structure in this area. Three clades were restricted to Morocco and appear to have originated at the Atlantic Coast of this country, while the fourth was found throughout the region. We propose a model with two colonizing events to explain the distribution patterns across the Strait of Gibraltar, with an initial colonization from North Africa to Iberia followed by a reinvasion of the Rif Mountains region in Morocco.

Reference:
Sousa P, Harris DJ, Froufe E, Van der Meijden A. Phylogeographic patterns of Buthus scorpions (Scorpiones: Buthidae) in the Maghreb and South-Western Europe based on CO1 mtDNA sequences. J Zool. 2012. Published ahead of print. [Subscription required for full text]


Family Buthidae

Scorpions of Iran - Part VIII: Fars Province

Part VIII of a major review of the scorpions of Iran has been published in issue 139 of the journal Euscorpius.

The paper lists 18 species (four new records for the province) in three families from the Fars Province and their distribution.

An identification key for the species in the province is given. Some good habitat pictures are presented.

Abstract:
18 species of scorpions belonging to three families are reported from the Fars Province of Iran. Of these, four species are recorded from the province for the first time: Compsobuthus persicus Navidpour, Soleglad, Fet et Kovařík, 2008, Mesobuthus eupeus persicus (Pocock, 1899), Odontobuthus bidentatus Lourenço et Pézier, 2002, and Scorpio maurus townsendi (Pocock, 1900). Also presented is a key to all species of scorpions found in the province.

Reference:
Navidpour S, Fet V, Kovarik F, Soleglad ME. Scorpions of iran (Arachnida, Scorpiones). part VIII. Fars Province. Euscorpius. 2012(139):1-29. [Free full text]

New Vaejovis from the Hualapai Mountains in Arizona

Davis Sissom and co-workers have described a new species of Vaejovis C. L. Koch, 1836 (Vaejovidae) from the Hualapai Mountains in Arizona (USA).

Vaejovis tenuipalpus Sissom, Hughes, Bryson Jr. & Prendini, 2012

Photo: Rich Ayrey (C)

Abstract:
A new species in the vorhiesi group of Vaejovis C.L. Koch, 1836 (Vaejovidae Thorell, 1876), which appears to be endemic to the Hualapai Mountains near Kingman, Arizona, is described and illustrated. Vaejovis tenuipalpus, n. sp., the 11th species in the vorhiesi group, is compared to morphologically similar species, including V. jonesi Stahnke, 1940, V. lapidicola Stahnke, 1940, V. vorhiesi Stahnke, 1940, and V. deboerae Ayrey, 2009. The new species possesses the most slender pedipalp chelae in the vorhiesi group. New distribution records and a comprehensive distribution map are provided for all Arizona members of the group.

Reference:
Sissom WD, Hughes GB, Bryson Jr RW, Prendini L. The vorhiesi group of Vaejovis C. L. Koch, 1836 (Scorpiones: Vaejovidae), in Arizona, with description of a new species from the Hualapai Mountains. American Museum Novitates. 2012(3742):1-19. [Free full text]

Thanks to Gerard Dupre for sending me this paper!Thanks to Rich Ayrey for sharing a picture of the new species with us!

Family Vaejovidae