16 October, 2018

A global review of medically important scorpions and scorpionism

Micaiah Ward and co-workers at Florida State University recently published an extensive review of medically important scorpions, epidemiology and scorpionism. The number of medical important species is raised to 104 (Buthidae: 101, Hemiscorpiidae: 2, Scorpionidae: 1). Of these, 36 species are considered dangerous (causing class II and III symptoms).

It is important to understand that a list like this can not be perfect. The species identification in many sting cases can be missing or wrong. Taxonomy is changing, and a species may turn out to be a species complex with potentially different venom potency (e.g. The Buthus occitanus complex). We should be careful not to label all species not on this list as harmless. A dangerous species may never have stung a human or the sting case was never reported. Also, many stings are dry or a reduced amount of venom is used, causing minor/mild symptoms and by this camouflaging a dangerous species. The article discuss some of these conserns.

 The article also has information about the distribution of medically important species, venom composition and the use of scorpion venom in biomedical research.

Scorpions are an ancient and diverse venomous lineage, with over 2200 currently recognized species. Only a small fraction of scorpion species are considered harmful to humans, but the often life-threatening symptoms caused by a single sting are significant enough to recognize scorpionism as a global health problem. The continued discovery and classification of new species has led to a steady increase in the number of both harmful and harmless scorpion species. The purpose of this review is to update the global record of medically significant scorpion species, assigning each to a recognized sting class based on reported symptoms, and provide the major toxin classes identified in their venoms. We also aim to shed light on the harmless species that, although not a threat to human health, should still be considered medically relevant for their potential in therapeutic development. Included in our review is discussion of the many contributing factors that may cause error in epidemiological estimations and in the determination of medically significant scorpion species, and we provide suggestions for future scorpion research that will aid in overcoming these errors.

Ward MJ, Ellsworth SA, Nystrom GS. A global accounting of medically significant scorpions: Epidemiology, major toxins, and comparative resources in harmless counterparts. Toxicon. 2018;151:137-55. [Subscription required for full text]

Thanks to Matt Simon for informing me about this article!

10 October, 2018

A review of the scorpions (and other arachnid groups) from Sudan

The Republic of the Sudan is one of the largest countries in East Africa with a large diversity when it comes to habitats and climate. A few new scorpion taxa have been described from Sudan in the last years, but no recent review of the scorpion fauna has been published.

Jason Dunlop and co-workers have recently published a review of the scorpions and other arachnid groups from Sudan. 17 species from the families Buthidae (15) and Scorpionidae (2) were recorded.

Literature-based species lists for arachnids, excluding spiders and mites, found in the Republic of the Sudan are provided. We summarize records, references, and localities for 17 scorpions (Scorpiones), one harvestman (Opiliones), nine pseudoscorpions (Pseudoscorpiones), 21 camel spiders (Solifugae) and one whip spider (Amblypygi). There are no published records of palpigrades (Palpigradi), whip scorpions (Thelyphonida), schizomids (Schizomida) or ricinuleids (Ricinulei), although at least whip scorpions and ricinuleids would not be expected in East Africa based on their current distribution. Key literature for mites and ticks (Acari) is also mentioned. In general, the Sudanese arachnid fauna has not been documented in detail. Many more species, particularly among the harvestmen and pseudoscorpions, are to be expected, and we offer the data gathered here as a baseline for future work.

Dunlop JA, Siyam M, Kovarik F. Smaller orders of Arachnida in Sudan: a literature review. Arachnology. 2018;17:449-57.

Thanks to Frantisek Kovarik for sending me their article!

08 October, 2018

Several synonymizations and redescriptions in the family Buthidae

Frantisek Kovarik has conducted a critical review on several taxa in the family Buthidae. These are the main conclusions:

Buthacus armasi Lourenço, 2013 is synonymized with Buthacus leptochelys (Ehrenberg, 1829).

Buthacus maliensis Lourenço & Qi,2007 is synonymized with Androctonus aleksandrplotkini Lourenço & Qi, 2007.

Compsobuthus williamsi Lourenço, 1999 is synonymized with Compsobuthus matthiesseni (Birula, 1905).

In addition a couple of old synonymzations are confirmed and several taxa have been revised and new descriptions are presented.

The taxonomic position of Buthacus armasi Lourenço, 2013, B. clevai Lourenço, 2001, B. huberi Lourenço, 2001, B.maliensis Lourenço & Qi, 2007, B. nigerianus Lourenço & Qi, 2006, Compsobuthus andresi Lourenço, 2004, C.simoni Lourenço, 1999, C. tassili Lourenço, 2010, C. tofti Lourenço, 2001, C. williamsi Lourenço, 1999, and Sabinebuthus elegans Lourenço, 2001 is revised and fictitious characters in their original descriptions are discussedand corrected. Buthacus armasi Lourenço, 2013 is synonymized with Buthacus leptochelys (Ehrenberg, 1829) syn. n., B. huberi Lourenço, 2001 is confirmed to be a synonym of Buthacus occidentalis Vachon, 1953, B. maliensis Lourenço & Qi,2007 is synonymized with Androctonus aleksandrplotkini Lourenço & Qi, 2007 syn. n., Compsobuthus williamsi Lourenço, 1999 is synonymized with Compsobuthus matthiesseni (Birula, 1905) syn. n., and Sabinebuthus elegans Lourenço, 2001 is confirmed to be a junior synonym of Lanzatus somalicus Kovařík, 2001.

Kovarik F. Notes on the Genera Buthacus, Compsobuthus, and Lanzatus with Several Synonymies and Corrections of Published Characters (Scorpiones: Buthidae). Euscorpius. 2018(269):1-12. [Open Access]

Family Buthidae

04 October, 2018

Sexual dimorphism and reproductive behavior in Tityus pusillus from Brazil

Behavior studies of scorpions are not that common and we still have much to learn about different types of scorpion behavior. Andre Lira and co-workers have now published a new study investigating the sexual dimorphism and reproductive behavior in Tityus pusillus Pocock, 1893 (Buthidae) from Brazil. They have mapped the different behavior components involved in reproduction in this species and have analyzed the sexual dimorphism present in T. pusillus. See abstract and article for further details.

We studied sexual dimorphism (SD) and reproductive behavior in the litter-dwelling scorpion, Tityus pusillus. SD was determined by measuring seven body structure attributes (prosoma, mesosoma, and metasoma lengths, and pedipalp chelae and metasomal segment V lengths and widths) in 634 individuals (211 males and 423 females) from the Arachnological Collection of the Universidade Federal de Pernambuco. Reproductive behavior was observed in 55 couples during nocturnal activity observations conducted in the laboratory. In addition, we evaluated gestation time, hemispermatophore replacement, and sequential courtship. Individuals of T. pusillus exhibited typical reproductive behavior, with a short courtship time (averaging 10 5 min). Males only accepted new partners at least 48 h after first mating, suggesting that this period may be necessary for hemispermatophore production. Females did not accept new partners for 24–48 h after their first mating. The average gestation period was 85 12 d, ranging 60–100 d. Our results showed a more complex picture of SD than previously described for this species, including features characteristic of both sexual size dimorphism (SSD) and sexual body component dimorphism in scorpions. In general, considering the relatively large size of the prosoma and mesosoma in T. pusillus, it seems reasonable to conclude that female-biased SSD exists in the species, and that male-biased sexual body component dimorphism is evident in the metasoma and chelae.

Lira AF, Pordeus LM, Rego FN, Iannuzzi K, Albuquerque CMJIB. Sexual dimorphism and reproductive behavior in the Brazilian scorpion Tityus pusillus (Scorpiones, Buthidae). Invertebr Biol. 2018;137(3):221-30. [Subscritpion required for full text]

Thanks to Andre Lira for sending me their article!

21 September, 2018

Three new species of Chaerilus from Malaysia and Thailand

Frantisek Kovarik and co-workers have recently published a new article describing three new species of Chaerilus Simon, 1877 (Chaerilidae) from Malaysia and Thailand.

Chaerilus majkusi Kovarik, Lowe & Stahlavsky, 2018 (Malaysia)

Chaerilus neradorum Kovarik, Lowe & Stahlavsky, 2018 (Thailand)

Chaerilus stockmannorumi Kovarik, Lowe & Stahlavsky, 2018 (Thailand)

The articles have pictures of live speciemens of the new species.

Chaerilus majkusi sp. n. from Malaysia (Tioman Island), C. neradorum sp. n. and C. stockmannorum sp. n. from Thailand are described and fully illustrated with color photographs of live and preserved specimens, as well as of their habitat. They are compared to the species C. cimrmani Kovařík, 2012, C. sejnai Kovařík, 2005, and C. tichyi Kovařík, 2000, which we also illustrate with color photographs of live unpublished specimens. Hemispermatophores of C. cimrmani, C. majkusi sp .n., C. stockmannorum sp. n., and C. tichyi are illustrated and compared, and we also describe the karyotypes of C. cimrmani, C. majkusi sp. n., C. neradorum sp. n., C. stockmannorum sp. n., C. sejnai and C. tichyi. The diploid numbers of chromosomes range from 76 to 186 and the karyotypes show distinct inter-specific variability among analyzed species. C. stockmannorum sp. n. (2n=186) possesses the highest number of chromosomes within the order Scorpiones and the class Arachnida.

Kovarik F, Lowe G, Stahlavsky F. Three New Chaerilus from Malaysia (Tioman Island) and Thailand (Scorpiones: Chaerilidae), with a Review of C. cimrmani, C. sejnai, and C. tichyi. Euscorpius. (268):1-27. [Open Access]

Family Chaerilidae

13 September, 2018

A review on the epidemiology and distribution of medical important scorpions in North America

It is well known that North America and especially Mexico is a hotspot for medical important scorpions. Canada has no dangerous species, while USA has only one (Centruroides sculpturatus Ewing, 1928). Mexico, on the other side, has several species that have great consequences for the public health.

Gonzalez-Santillan & Possani have recently published a review summing up the current knowledge on the distribution and epidemiology of the medical important scorpions of North America. 21 species and one subspecies, all in the genus Centruroides, are identified as medical important, and their distribution is given. The different aspects of scorpionism in North America is also discussed.

Scorpionism is a severe threat to public health in North America. Historically, few species of Centruroides have been considered to be the offending taxa, but we know now that their diversity is greater and our knowledge incomplete. Current distribution maps are inadequate for some species. Epidemiologic studies are sporadic and local, and a complete synthesis for North America is missing. We analyze historical and recent knowledge about the identity, distribution and epidemiology of species of medical importance in North America. PubMed, Google Scholar, the National Collection of Arachnids, and results of recent field work were consulted in the preparation of our analysis. We recognized 21 species and one subspecies of medically important scorpions in need of precise geographical delimitation. All these species are found in Mexico, which is clearly a hotspot for scorpionism. Although mortality has been steadily decreasing, deaths still occur, and morbidity remains high. Mortality is most common at age classes of 0–10 years and>50. Morbidity is highest in age class 15–50 years, including the most economically active segment of the population. The season of the highest incidence of scorpion sting peaks between spring and summer but there appears to be a second, lower peak at the end of the summer. Although the systematics of the genus Centruroides has advanced considerably, our knowledge of its diversity remains fragmentary. There is a disconnection between the actual distribution of the scorpions and the incidence maps constructed from scorpion sting records. Despite a historically robust knowledge of the distribution of wellknown species, most recently described species are known from only a few localities. Some of the epidemiological parameters are consistent among studies reported herein.

Gonzalez-Santillan E, Possani LD. North American scorpion species of public health importance with a reappraisal of historical epidemiology. Acta Trop. 2018;187:264-74. [Subscription required for full text]

17 August, 2018

Genus Babycurus split into a new genus and two new species from the Arabian Peninsula

Frantisek Kovarik and co-workers recently published a review of the genus Babycurus Karsch, 1886 (Buthidae) resulting into splitting this genus into two genera. The taxanomical decisions from this study are:

Barbaracurus Kovarik, Lowe & Stahlavsky, 2018 (New genus distributed mainly in the Arabian Peninsula and The Horn of Africa). Species included after review:
B. exquisitus (Lowe, 2000) (Previously in Babycurus)
B. prudenti Lourenço, 2013 (Previously in Babycurus)
B. somalicus (Hirst, 1907) (Previously in Babycurus)
B. sofomarensis (Kovarik, Lowe, Seiter, Pliskova &Stahlavsky, 2015) (Previously in Babycurus)
B. subpunctatus (Borelli, 1925) (Previously in Babycurus)
B. ugartei (Kovarik, 2000) (Previously in Babycurus)
B. winklerorum Kovarik, Lowe &Stahlavsky, 2018 (New species from Oman)
B. yemenensis Kovarik, Lowe, Seiter, Pliskova &Stahlavsky, 2015 (New species from Yemen)
B. zambonellii (Borelli, 1902) (Previously in Babycurus)

Babycurus Karsch, 1886 (Strictly African distribution). Species included after review:
B. ansorgei Hirst, 1911
B. brignolii Lourenço & Rossi, 2017 (Declared Nomen Dubia)
B. buettneri Karsch, 1886
B. centrurimorphus Karsch, 1886
B. dunlopi Kovarik, Lowe, Seiter, Pliskova &Stahlavsky, 2015
B. gigas Kraepelin, 1896
B. jacksoni (Pocock, 1890)
B. kirki (Pocock, 1890)
B. melanicus Kovarik, 2000
B. multisubaculeatus Kovarik, 2000
B. pictus Pocock, 1896
B. solegladi Lourenço, 2005
B. taramassoi Borelli, 1919
B. wituensis Kraepelin, 1913

Babycurus ornatus Werner, 1936 is declared as a junior synonym of Lychas burdoi (Simon, 1882).

The article has an identification key for Barbaracurus.

The genus Babycurus Karsch, 1886 sensu lato is split into two genera, a strictly African genus Babycurus, and the new genus Barbaracurus gen. n., which mainly includes species from the Horn of Africa and Arabian Peninsula. Two new species Barbaracurus winklerorum sp. n. from Oman and B. yemenensis sp. n. from Yemen are described, compared with other species, and fully illustrated with color photos of morphology, habitus, live specimens and collection localities. Males of Barbaracurus somalicus (Hirst, 1907) comb. n. and Barbaracurus zambonellii (Borelli, 1902) comb. n. are recorded for the first time and fully illustrated. Babycurus ornatus Werner, 1936 from Mozambique is shown to be a junior synonym of Lychas burdoi (Simon, 1882), a species from the same area. Babycurus brignolii Lourenço et Rossi, 2017 is designated to be a nomen dubium. Hemispermatophores are des-cribed and illustrated to show their differences between the species and genera. Analyses of karyotypes reveal a similar degree of interspecific variability of diploid chromosomal numbers within the genera Babycurus (2n=16–30) and Barbaracurus gen. n. (2n=22–36).

Kovarik F, Lowe G, Stahlavsky F. Review of the genus Babycurus Karsch, 1886 (Arachnida, Scorpiones, Buthidae), with descriptions of Barbaracurus gen. n. and two new species from Oman and Yemen. Euscorpius. 2018(267):1-41. [Open Access]

Family Buthidae