24 April, 2017

A new species of Babycurus from Central African Republic

Lourenco and Rossi have recently described a new species of Babycurus Karsch, 1886 (Buthidae) from North Savannah formations in Central African Republic.

Babycurus brignolii Lourenco & Rossi, 2017

A new species, Babycurus brignolii sp. n., is described from North Savannah formations in Central African Republic. This is the second record of a Babycurus species from Central African Republic. The new species is characterized by a small total body size, with respect to other species within the genus, and a general yellow to yellow-testaceous coloration with some diffuse fuscosity. This species, a possible endemic element from the savannah formations of Northern Central African Republic, provides further evidence regarding the unsuspected scorpion richness of this region.

Lourenco WR, Rossi A. A new species of Babycurus Karsch, 1886 from dry Savannahs in Central African Republic (Scorpiones: Buthidae). Onychium. 2017;13:3-8. [Open Access]

Thanks to Andrea Rossi for sending me this article!

Family Buthidae

21 April, 2017

Scorpion defensive behaviour and its relation to morphology and performance

Scorpions are infamous for their tail and venomous sting. The sting is used for defense and prey capture, and in some cases during mating. The scorpions tail comes in many shapes and sizes. And different species use their tail different (they sting in different ways).

In a recent study, Pedro Coelho and co-workers have investigated the movement trajectory and kinematics of the defensive strike in seven species of scorpions from two families. Not surprisingly, they discovered that the defensive use of the sting varied between the species. The article try to explain the observed differences by looking at differences in morphology, habitat, behavior and other factors.

PS! Take a look at the excellent video on YouTube explaining the project!

1. Like many other venomous organisms, scorpions use their venom in defence against predators. Scorpions apply their venomous stinger by extending the caudal part of the body, the metasoma, forward towards the attacker. There are considerable differences in metasoma morphology among scorpion species, and these may afford differences in defensive strike performance.
2. We investigated the movement trajectory and kinematics of the defensive strike in seven species of scorpions, and how these variables are related to each other, and to morphology.
3. We recorded defensive strikes using high-speed video, and reconstructed the trajectory of the telson. From these trajectories, we calculated velocity, acceleration and other kinematic variables. To compare strike trajectory shapes, we used geometric morphometrics.
4. We have shown that the defensive strike differs in trajectory shape, speed, path length and duration between scorpion species. Body size is also an important factor affecting strike characteristics. Relative metasoma length and girth may also influence strike performance, as well as strike trajectory shape. Strikes with different trajectories have different kinematic properties: those with open trajectory shapes attain higher speeds.
5. Our results show that performance differences in defensive behaviour between different scorpion species may be partly mediated by morphology, binding together phenotypic, functional and behavioural diversity.

Coelho P, Kaliontzopoulou A, Rasko M, van der Meijden A. A ‘striking’ relationship: scorpion defensive behaviour and its relation to morphology and performance. Functional Ecology. 2017; Early View. [Subscription required for full text]

19 April, 2017

What is the best treatment for scorpion envenomations?

Scorpions are still a significant cause for mortality, especially in developing countries. The are several treatment strategies available for serious scorpion stings. Some involves the use of anti-venom, while others are based on symptomatic treatment. Studies so far has shown that one treatment strategy works for some species, but are less effective for others.

Rodrigo and Gnanathasan have recently published a systematic review on scorpion envenomations trying to find the best evidence available for the efficiency of the different treatment strategies used against serious scorpion envenomation around the world.

The main conclusion is that the polyvalent antivenom against Centruroides sp. in USA/Mexico and the monovalent antivenom against Hottentotta tamulus in India are effective for rapid resolution of symptoms. Prazosin is useful as an add-on therapy for H. tamulus stings. I recommend reading the article for further details.

Background: Scorpion stings cause an estimated 3000 deaths per annum worldwide. We conducted a systematic review of all controlled clinical trials related to scorpion sting management.
Methods: We searched PubMed, EMBASE, Scopus, Web of Science and CINAHL and included controlled prospective clinical trials (randomized or non-randomized). The following interventions were assessed: adults and children with scorpion stings treated with (a) steroids vs. placebo, (b) different methods of pain relief, (c) antivenom vs. supportive treatment, (d) prazosin vs. supportive treatment, (e) antivenom vs. prazosin and (f) antivenom plus prazosin vs. prazosin alone. When trials had comparative outcomes, they were combined in a meta-analysis. Data was analysed with Review Manager 5. Dichotomous data were compared with relative risk (RR), and continuous data were compared with mean differences using a fixed effect model. There is no PROSPERO registration number for this study.
Results: Antivenom against Centruroides sp. are effective in reversing the clinical syndrome faster than no antivenom treatment in children (RR, 0.02; 95% CI, 0.01 to 0.06; 322 participants; three trials). Antivenom (against Mesobuthus tamulus) and prazosin combination is better than prazosin alone for faster resolution of symptoms (mean difference, −12.59 h; 95% CI, −14.01 to −11.17; 173 participants; three trials).
Conclusions: The polyvalent antivenom against Centruroides sp. in USA/Mexico and the monovalent antivenom against M. tamulus in India are effective for rapid resolution of symptoms. Prazosin is useful as an add-on therapy for M. tamulus stings.

Rodrigo C, Gnanathasan A. Management of scorpion envenoming: a systematic review and meta-analysis of controlled clinical trials. Systematic Reviews. 2017;6(1):74. [Open Access]

07 April, 2017

A new species of Pandinurus from Somaliland

Frantisek Kovarik and his co-workers studying the scorpion fauna of The Horn of Africa recently published a new species in the genus Pandinurus Fet, 1997 (Scorpionidae).

Pandinurus kmoniceki Kovarik, Lowe, Mazuch, Pliskova & Stahlavsky, 2017

The article is well illustrated with color pictures.

Pandinurus kmoniceki sp. n. from Somaliland is described and fully complemented with color photos of live and preserved specimens, as well as its habitat. Hemispermatophore of P. kmoniceki sp. n. is illustrated and described. In addition to the analyses of external morphology and hemispermatophores, we also describe the karyotypes of P. kmoniceki sp. n. (2n=120).

Kovarik F, Lowe G, Mazuch T, Pliskova J, Stahlavsky F. Scorpions of the Horn of Africa (Arachnida: Scorpiones). Part XI. Pandinurus kmoniceki sp. n. (Scorpionidae) from Somaliland. Euscorpius. 2017(243):1-14. [Open Access]

Family Scorpionidae

06 April, 2017

A new genus and species from the Argentinean Precordillera

Andres Ojanguren Affilastro and Camilo Mattoni have recently described a new genus and a new species from the Argentinean Precordillera.

Mauryius Ojanguren-Affilastro & Mattoni, 2017

Mauryius cuyanus Ojanguren-Affilastro & Mattoni, 2017

Mauryius n.gen., a new bothriurid scorpion genus from the Argentinean Precordillera, is described, and its phylogenetic position is discussed based on a phylogenetic analysis of morphological data. Mauryius n.gen. is the first scorpion genus endemic to the Argentinean Precordillera. It is most closely related to Pachakutej Ochoa, 2004 from the inter-Andean valleys of Peru and to Rumikiru Ojanguren-Affilastro, Mattoni, Ochoa & Prendini, 2012 from the Atacama Desert in Chile. Mauryius cuyanus n.sp., the only known species of the genus, is described. Biogeographical implications of Mauryius relationships are discussed.

Ojanguren-Affilastro AA, Mattoni C. Mauryius n.gen. (Scorpiones: Bothriuridae), a new neotropical scorpion genus. Arthropod Systematics & Phylogeny. 2017;75(1):125-39.[Open Access]

Thanks to Gerard Dupre for sending me this article!

Family Bothriuridae