30 November, 2017

Burrowing in two scorpion species from Iran

Babak Vazirianzadeh and co-workers have recently published a study of the habitat choice and burrowing behavior of the two scorpions Scorpio maurus Linnaeus, 1758 (Scorpionidae)  and Odonthubutus bidentatus (Lourenço & Pezier, 2002) (Buthidae) from Iran.

Background: The different features of scorpions can be successfully described by their nesting and burrowing behaviors. There is little information about burrowing activity of Iranian scorpions.
Methods: The current study was performed to compare the burrowing behavior between two burrowing Iranian scorpions, Scorpio maurus and Odonthubutus bidentatus by describing 30 nests of each species regarding collecting the scorpions.
Results: Scorpio maurus and O. bidentatus have a tendency to make nest with elliptical, round-like entrance and oval shape with arch at the top, respectively. There was not any significant difference between nest entrance properties of two scorpions. One-way ANOVA test showed that the height and diameter of two species nests were not significantly different. A Pearson correlation also showed a relative strong direct relationship between height and diameter of S. maurus nests than O. bidentatus. This correlation was not significant in the case of O. bidentatus. The results provided additional habitat information of scorpions.
Conclusion: The nests morphology characteristics of two Iranian scorpions including shape, depth, length and diameter depend are different from each other based on the following factors: species, soil texture, soil moisture and region conditions.

Vazirianzadeh B, Jalali A, Chrom M, Mohammady A, Vatandoost H, Panahi F. A Comparative Study of Nesting Sites and Burrowing Habits of Two Iranian Burrowing Scorpions. Journal of Arthropod-Borne Diseases. 2017;11(1):78-85. [Open Access]

27 November, 2017

The scorpions of Hispaniola (Dominican Republic and Haiti)

Gabriel de los Santos and co-workers published an annotated list of the known scorpions from Hispaniola (Dominican Republic and Haiti) in 2016. I just recently learned about this article, hence the late mentioning in the blog. The article is in Spanish.

It is given an annotated list of the known scorpions of Hispaniola (Dominican Republic and Haiti), which belong to three families (Buthidae, Hormuridae, Scorpionidae), eight genera and 46 recent and four fossil species. Buthidae (five genera and 37 living species) is the most diversified family in this Antillean island, being Tityus C. L. Koch, 1836, Microtityus Kjellesvig-Waering, 1966, and Centruroides Marx, 1890, the most diverse and widespread genera with 14, 12 and seven species, respectively. The Dominican Republic (that represents the eastern two-thirds of the island), has 45 species and 36 of them are endemic from the country, whereas Haiti accounts nine species with a single national endemism. Isometrus maculatus (De Geer, 1778) has been introduced in both countries and is the only non-endemic species. This is the only Antillean island which includes representatives of both the Hormuridae family and the fossil fauna (in amber).

de los Santos G, de Armas LF, Teruel R. Lista anotada de los escorpiones (Arachnida: Scorpiones) de la Española (República Dominicana y Haití). Novitates Caribaea. 2016;10:1-22. [Open Access]

Thanks to Mack Diamond for informing me about this paper!

21 November, 2017

A new genus and species of fossil scorpion from Italy

Gabriele Kühl and Wilson Lourenco recently described a new genus and species of fossil scorpion from the Early–Middle Eocene of Pesciara in Italy. The new taxa belongs to the family Euscorpiidae, and this is the first fossil/extinct taxa belonging to this extant family.

Eoeuscorpius Kühl & Lourenco, 2017

Eoeuscorpius ceratoi Kühl & Lourenco, 2017

Fossil scorpions are among the oldest terrestrial arthropods known from the fossil record. They have a worldwide distribution and a rich fossil record, especially for the Paleozoic. Fossil scorpions from Mesozoic and Cenozoic deposits are usually rare (except in amber-deposits). Here, we describe the only fossil scorpion from the Early to Middle Eocene Pesciara Lagersta¨tte in Italy. Eoeuscorpius ceratoi gen. et sp. nov. is probably a genus and species within the family Euscorpiidae. This may be the first fossil record of the Euscorpiidae, which are so far only known from four extant genera. Eoeuscorpius ceratoi gen. et sp. nov. was found in the ‘‘Lower Part’’ of the Pesciara Limestone, which is actually dated Late Ypresian stage (between 49.5 and 49.7 Ma). Besides a possible pseudoscorpion, the here-described fossil scorpion is the second arachnid species known from the Bolca Locality.

Kühl G, Lourenço WR. A new genus and species of fossil scorpion (?Euscorpiidae) from the Early–Middle Eocene of Pesciara (Bolca, Italy). PalZ. 2017;91(3):283-90. [Subscription required for full text]

17 November, 2017

The life history of the parthenogenetic scorpion Lychas tricarinatus and some new data on parthenogenesis in Tityus trivittatus

Michael Seiter and Mark Stockman have recently published an article on life history and parthenogenesis in the two buthids Lychas tricarinatus (Simon, 1884) from Odisha province, India and Tityus trivittatus Kraepelin, 1898 from Argentina.

The study clearly demonstrated that Lychas tricarinatus can reproduce without being inseminated by males after observations of captive-born females raised in isolation over three generations. Observations on the entire life cycle of most scorpion species are scarce, and the data shown for Lychas tricarinatus in this study are quite unique.

The Tityus trivittatus used in this study were confirmed to be facultative parthenogenetic, producing both male and female offspring. The capability of a single population to reproduce by sexual as well as by asexual reproduction is probably a strategy to adapt to environmental circumstances enabling genetic variation.

Observations on the entire life cycle of most scorpion species are scarce. Here, we present precise data of the embryonic and postembryonic development for Lychas tricarinatus with additional notes on Tityus trivittatus. By rearing captive-born Lychas tricarinatus specimen from the Odisha province (India) in isolation until maturation, we could show that virgin females gave birth to offspring proving that specimens are capable of parthenogenetic reproduction. Further, we describe an all-female population of Tityus trivittatus from the Corrientes province (Argentina), which originated from a fully bi-sexual population. In addition we describe the ontogenetic development of these two parthenogenetic, buthid scorpions under laboratory conditions. The Dyar’s constant was evaluated for the carapace, metasomal segment V, and the movable finger of the pedipalp among the instars. The calculated growth factor has a total grand average of 1.26. Lychas tricarinatus females reached maturity after 220 days postembryonic development. Moreover, L. tricarinatus females started to reproduce in the 6th or 7th instar and gave birth to an average of 21 neonates after 96 days of embryonic development. Tityus trivittatus matured in the 5th or 6th instar and gave birth after 230 days to an average of 13 neonates.

Seiter M, Stockmann M. The life history of the parthenogenetic scorpion Lychas tricarinatus (Simon, 1884) from Odisha province, India and supplementary notes on Tityus trivittatus Kraepelin, 1898 (Scorpiones, Buthidae). Zoologischer Anzeiger. 2017;270:155-65. [Subscription required for full text]

Thanks to Mark Stockman for sending me this article!

14 November, 2017

Geographic distribution of the genus Mesobuthus in Mongolia

Heddergott and co-workers published a study on the geographic distribution of the genus Mesobuthus Vachon, 1950 (Buthidae) in 2016. I just recently learned about it and want to mention it in the blog as there are very few articles on the scorpion fauna of Mongolia. The results are summed up in the abstract.

In the present study, we surveyed the diversity of scorpions in six provinces of Mongolia (Bayankhongor, Khovd, Dundgovi, Dornogovi, Govisümber and Ömnögovi) between 2001 and 2012. A total of 385 individuals were collected at 17 different sites. In addition to opportunistic sampling, animals were collected after detection with ultraviolet light. Only species from the genus Mesobuthus have been reported from Mongolia thus far. It was possible to confirm the occurrence of the species Mesobuthus eupeus mongolicus and report the presence of M. martensii martensii for the first time. We could not confirm the presence of M. caucasicus przewalskii and suggest that it does not occur in the country, since earlier records originated from present-day China. We provide initial information on the ecology of the two species we identified. Individuals of M. eupeus mongolicus from western Mongolia have a darker pigmentation of the metasomal segments I-IV than individuals from central or southern Mongolia.

Heddergott M, Stubbe M, Stubbe W, Steinbach P, Stubbe A. Geographical Distribution of the Genus Mesobuthus (Scorpiones: Buthidae) in Mongolia. Erforschung biologischer Ressourcen der Mongolei. 2016(13):147-64. [Open Access]

Family Buthidae

Geographic distribution of scorpion envenomations in the USA

Kang and Brooks recently published a epidemiological study on the geographic distribution of scorpion envenomations in the USA in 2010-2015. Most cases were reported from Arizona (57 168), where the infamous Arizona Bark Scorpion (Centruroides sculpturatus Ewing, 1928) is medical important species. Eight other US states also had scorpion envenomations (ranging from 9659 to 906 cases).

Health consequences of scorpion envenomations are also discussed.

Objectives. To determine the geographic distribution of scorpion envenomations in the United States by zip code, with particular attention to the neurotoxic Centruroides sculpturatus (Arizona bark scorpion), for which an antivenom is available.
Methods. We obtained scorpion exposure cases for 2010 to 2015 from the National Poison Data System. Using geographic information systems software, we mapped total exposures and incidence rates for 9 states that reported more than 100 annual calls. We also mapped cases that reported fasciculations and nystagmus (unique to C. sculpturatus among native scorpions).
Results. The highest exposure incidences occurred in Phoenix (up to 677 per 100 000 population) and Tucson (584), both in Arizona. Elsewhere, high incidences were found in El Paso, Texas (213); Oklahoma City (209) and Tulsa (178), Oklahoma; and Las Vegas, Nevada (170). Fasciculations and nystagmus were reported in Arizona and southeastern Nevada, with small numbers in surrounding states, including Utah.
Conclusions. Scorpion exposures occurred at baseline rates throughout many of the southern states, whereas several states reported effects indicative of Arizona bark scorpion envenomation.

Kang AM, Brooks DE. Geographic Distribution of Scorpion Exposures in the United States, 2010-2015. Am J Public Health. 2017;107(12):1958-63. [Subscription required for full text]

03 November, 2017

Scorpion envenomations in southeastern Ecuador

Juan Roman and co-workers have studied scorpion envenomations in rural locations in the Amazonian province of Morona Santiago, southeastern Ecuador. The severity of scorpion stings in this region is reported and the conclusion is that scorpions are a public health problem, especially for young children.

A phylogenetic analysis of the scorpions involved in serious cases were conducted and revealed that these were caused by a species in the Tityus obscurus group (Buthidae). This group contains species responsible for severe envenomations in other areas of the Amazonian Basin. The Ecuadorian species involved is unknown, and will be described as a new species in a future publication.

Scorpion envenoming by species in the genus Tityus is hereby reported from rural locations in the Amazonian province of Morona Santiago, southeastern Ecuador. Twenty envenoming cases (18 patients under 15 years of age) including one death (a 4-year-old male) were recorded at the Macas General Hospital, Morona Santiago, between January 2015 and December 2016 from the counties of Taisha (n =17), Huamboyo (n= 1), Palora (n =1), and Logroño (n =1). An additional fatality from 2014 (a 3-year-old female from Nayantza, Taisha county) is also reported. Leukocytosis and low serum potassium levels were detected in most patients. We observed a significant negative correlation between leukocytosis and hypokalemia. Scorpions involved in three accidents from Macuma, Taisha County, were identified as genetically related to Tityus obscurus from the Brazilian Amazonian region based on comparison of mitochondrial DNA sequences encoding cytochrome oxidase subunit I. These cases, along with previously reported envenoming from northern Manabí, reinforce the notion that scorpionism is a health hazard for children in Ecuador and emphasizes the need to supply effective antivenoms against local species, which are not currently available. The genetic affinity of the Ecuadorian specimens with T. obscurus may underlay toxinological, clinical, and venom antigenic relationships among Amazonian scorpions that deserves further exploration for designing therapeutic strategies to treat scorpionism in the region.

Roman JP, Garcia F, Medina D, Vasquez M, Garcia J, Graham MR, et al. Scorpion envenoming in Morona Santiago, Amazonian Ecuador: Molecular phylogenetics confirms involvement of the Tityus obscurus group. Acta Trop. 2017;178:1-9. [Subscription required for full text]

Thanks to Adolfo Borges and Matthew Graham for both sending me their article!