31 July, 2013

The history of scorpion antivenom in North America

Leslie Boyer has written a very interesting article on the history of scorpion antivenom. The paper's main focus is North America, but main globale events in the history of scorpion antivenom and treatment are also presented.

This paper was originally presented as the Elsevier Lecture in July, 2012 at the International Society on Toxinology/Venom Week combined meeting in Honolulu, Hawaii. In it, the author addresses the ancient history of venom and immunity, from the Silurian Era to the 1890s; the development of the first antivenoms; the impact of shifting political and economic pressures; the special case of Arizona; the relative stability of the 1960s through 1990s; the transition to regulatory compliance that took place at the time of the author’s own research; and concluding thoughts regarding the instability of apparent success.

Boyer L. History of scorpion antivenom: One Arizonan's view. Toxicon. 2013;69:14-20. [Subscription required for full text]

26 July, 2013

Tityus tenuicauda in Venezuela: Taxonomy, distribution and a synonymization

Pablo Cornejo-Escobar and co-workers have recently published a paper on the taxonomical- and distributional status of Tityus tenuicauda Prendini, 2001 (Buthidae) in Venezuela.

In the paper, Tityus irapaensis Gonzalez-Sponga, 2002 is synonymized with T. tenuicauda.

Tityus tenuicauda was originally described as a scorpion species endemic to the Caribbean Sea island of Trinidad. We extend the distribution range of T. tenuicauda westward until Las Melenas, a location in the western side of Paria Peninsula National Park, Sucre State, northeastern Venezuela. In addition, we determined that T. irapaensis González-Sponga, 2002, is a junior synonym of T. tenuicauda. The assessment of 56 adult individuals of T. tenuicauda from Venezuela demonstrated that this species is an arboreal dweller that frequently inhabits peridomicile areas. To provide a molecular counterpoint to our taxonomical assessment, we have characterized the nucleotide sequence (and its encoded protein primary structure) of a gene segment encoding subunit 1 of the enzyme cytochrome oxidase (COI), amplified from T. tenuicauda mitocondrial DNA. Comparison with the equivalent CO1 regions from congeneric Venezuelan species revealed that T. tenuicauda is significantly more related to the also northeastern species, T. arellanoparrai González-Sponga, 1985 and confirms its divergence from the northcentral species, T. discrepans Karsch, 1879, and the western species T. zulianus González-Sponga, 1981.

Cornejo-Escobar P, Borges A, Bonoli S, Vasquez-Suarez A, Gregorian T, De Sousa L. Tityus tenuicauda Prendini, 2001 (Scorpiones, Buthidae) en Venezuela. Notas taxonomicas con sinonimia, distribución e historia natural. Saber. 2013;25(1):57-72. [Free full text]

Family Buthidae

25 July, 2013

More knowledge about the scorpion fauna of Madagascar

Madagascar is a hotspot when it comes to scorpion biodiversity and professor Wilson Lourenco is the leading expert on the blooming scorpion fauna of this island. In a recent paper, professor Lourenco and Steven Goodman have summed up the knowledge about the scorpion fauna of the Loky-Manambato (Daraina) region of Madagascar.

An overview is presented of the scorpion fauna of the Loky-Manambato (Daraina) region of northeastern Madagascar. Different scorpion taxa have been recently described from this area, belonging to four families, five genera and five species (with four microendemics). The preliminary results make the Loky-Manambato region one of the areas of the island with the highest level of diversity and endemism. Information is presented on the characters used to differentiate these species, including an identification key, and aspects of their ecology. Even given the remarkable level of habitat heterogeneity across the Loky-Manambato region, for the majority of locally occurring taxa there does not seem to be a close correlation between different aspects of soil composition and organic material relative to their distribution.

Lourenco WR, Goodman SM. A synopsis of the scorpion fauna of the Loky-Manambato (Daraina) region in Madagascar. Revista Iberica de Arachnologia. 2013 (22):47-58.

Thanks to professor Lourenco for sending me his paper!

23 July, 2013

Scorpionism in Trinidad and Tobago

After two recent deaths due to scorpion envenomations in Trinidad and Tobago, Adolfo Borges has written a review on scorpionism in this country summing up the history of scorpion envenomations, treatment and current status. The most dangerous species is probably Tityus trinitatis Pocock, 1897 (Buthidae), which was believed to be the species involved in the above mentioned deaths.

This article reviews the scorpion fauna inhabiting Trinidad and Tobago, avialable health statistics, and the literature to assess scorpionism in these Caribbean islands, recently shaken by two infant deaths, probably due to envenomation by Tityus trinitatis Pocock. This domiciliary species, amply distributed in southern and northeastern Trinidad and Tobago, is responsible for an envenomation syndrome involving hyperstimulation of the autonomic nervous system and the triggering of an inflammatory response, similarly to other congeneric species of medical importance in the Neotropical region. Phylogeographic and venom immunochemical evidence indicate that Tronidad and Tobago are part of the northern South American endemic area of scorpionism and that their noxious scorpion fauna probably share toxilogical similarities with its northeastern Venezuelan counterparts. An evaluation is ussgested in the case of T. trinitatis to establish with certainty the efficacy and efficiency of antivenoms available in Latin America in neutralizing its lethal neurotoxic and cardiotoxic activities.

Borges A. New solutions to an old problem: Integrating evidence to assess the envenomation by noxious scorpions in Trinidad and Tobago. Carib Med J. 2013;75(1):13-9.

Thanks to Dr. Borges for sending me his paper!

Species delimitation and morphological divergence in Centruroides vittatus

Identifying the correct species is very important in the medical important family Buthidae, as correct identification may be essential for the medical treatment needed in case of envenomations. Species identification and delimitation in Buthidae is often a challenge to scientists because many species exhibit a considerable intraspesific variation in morphology.

Tsunemi Yamashita and Douglas Rhoads have now published a very interesting study conducting a phylogeographic, morphometric and ecological niche modelling analysis of the North American scorpion Centruroides vittatus (Say, 1821) (Buthidae). This paper presents a clarification of the status of the polymorphic C. vitattus in the USA, but also shows how additional methods can be used for understanding species delimitation in phylogeny and taxonomy.

Scorpion systematics and taxonomy have recently shown a need for revision, partially due to insights from molecular techniques. Scorpion taxonomy has been difficult with morphological characters as disagreement exists among researchers with character choice for adequate species delimitation in taxonomic studies. Within the family Buthidae, species identification and delimitation is particularly difficult due to the morphological similarity among species and extensive intraspecific morphological diversity. The genus Centruroides in the western hemisphere is a prime example of the difficulty in untangling the taxonomic complexity within buthid scorpions. In this paper, we present phylogeographic, Ecological Niche Modeling, and morphometric analyses to further understand how population diversification may have produced morphological diversity in Centruroides vittatus (Say, 1821). We show that C. vittatus populations in the Big Bend and Trans-Pecos region of Texas, USA are phylogeographically distinct and may predate the Last Glacial Maximum (LGM). In addition, we suggest the extended isolation of Big Bend region populations may have created the C. vittatus variant once known as C. pantheriensis.

Yamashita T, Rhoads DD. Species Delimitation and Morphological Divergence in the Scorpion Centruroides vittatus (Say, 1821): Insights from Phylogeography. PLoS One. 2013; 8(7): e68282. [Free full text]

Thanks to Rolando Teruel and Matt Simon for informing me about this paper!

22 July, 2013

New Euscorpius discovered

Gioele Tropea has looked into Euscorpius tergestinus (C. L. Koch, 1837) (Euscorpiidae) and discovered that this widespread, polymorphic species actually is two distinct species. Populations previously named Euscorpius carpathicus aquilejensis (C. L. Koch, 1837) (which has been in synonymy with E. tergestinus (C. L. Koch, 1837)), are now given species status. The new species' name is Euscorpius aquilejensis (C. L. Koch, 1837).

Euscorpius aquilejensis (C. L. Koch, 1837): Restricted to northern and central Italy, San Marino, Vatican City State, western Slovenia, northwestern Croatia.

Euscorpius tergestinus (C. L. Koch, 1837): Restricted to Italy (extreme northeast), Slovenia, Croatia, Austria (introduced) and Czech Republic (introduced)

Both morphological and genetic data confirm the validity of the two species.

After the revision of Fet & Soleglad (2002), Euscorpius tergestinus (C. L. Koch, 1837) was considered a polymorphic species widespread from France to Croatia. In this study, we reconsidered the taxonomy of E. tergestinus s.str. based on morphological and genetic evidence, its range, and its original description. Euscorpius aquilejensis (C. L. Koch, 1837), stat. nov., previously synonymous with E. tergestinus, is elevated to species status herein. A preliminary phylogenetic analysis based on available GenBank 16S rDNA data shows a separate, basal position of E. aquilejensis and some other Euscorpius species, which implies that the subgenus Euscorpius s.str. is paraphyletic.

Tropea G. Reconsideration of the taxonomy of Euscorpius tergestinus (Scorpiones: Euscorpiidae). Euscorpius. 2013 (162):1-23. [Free full text]

Family Euscorpiidae 

Thanks to Gioele Tropea for sending me his new article!

New species of Buthus from Egypt

I've been on holliday for a few weeks, but the publication of scorpion literature does not rest. There have been several new papers published during my vacation and I will blog about these in the week to come.

Andrea Rossi has discovered a new species of Buthus Leach, 1815 (Buthidae) from northern Egypt.

Buthus adrianae Rossi, 2013

There is now five valid Buthus species in Egypt, and an identification key for the species is provided in the paper.

A new species of the genus Buthus Leach, 1815 is described from northern Egypt, near to the Mediterranean coast. Buthus adrianae sp. n. shows morphological and geographical affinity with Buthus orientalis Lourenço & Simon, 2012 recorded from Alexandria. A discussion about the distribution of the species of the genus Buthus in Egypt and an identification key are also proposed.

Rossi A. A new species of the genus Buthus Leach, 1815 from Egypt (Scorpiones: Buthidae). Riv Mus Cic Sc Nat "E Caffi" Bergamo. 2013;26:187-94. [Free full text]

Thanks to Diego Facheris and Andrea Rossi for sending me this paper!