Three new species in the buthid genus Gint from Ethiopia and Somaliland

Frantisek Kovarik and co-workers have recently published a new article in their ongoing study of the scorpion fauna of The Horn of Africa. This time, three new species in the genus Gint Kovarik, Lowe, Pliskova & Stahlavsky, 2013 (Buthidae) are described from Somaliland and Ethiopia.

Gint abshiri Kovarik, Elmi & Stahlavsky, 2024 (Ethiopia)

Gint derbiae Kovarik, Elmi & Stahlavsky, 2024  (Ethiopia)

Gint sahil Kovarik, Elmi & Stahlavsky, 2024 (Somaliland)

The article has an updated identification key for the genus. 

Abstract:
Three new species, Gint sahil sp. n. from Somaliland and Gint abshiri sp. n. and G. derbiae sp. n. from Ethiopia are described and compared with other species of the genus. Additional information is provided on the taxonomy and distribution of the genus Gint, fully complemented with color photos of specimens of the new species, as well as of their habitats. Furthermore, alongside the analyses of external morphology and hemispermatophores, we have provided description of the karyotype of G. abshiri sp. n. This species exhibits karyotype with 2n=27. Included is distribution map and a key for the genus Gint.

Reference:
Kovarik F, Elmi HSA, Stahlavsky F. Scorpions of the Horn of Africa (Arachnida, Scorpiones). Part XXXIII. Three new species of Gint from Ethiopia and Somaliland (Buthidae). Euscorpius. 2024(392):1-25. [Open Access]

Family Buthidae

A new genus and three new species in the family Scorpionidae from Jordan

 

Bassam Abu Afifeh and co-workers recently published a revision of the genus Scorpio Linnaeus, 1758 (Scorpionidae) in Jordan. The widespread genus had only one species for many decades, but were poorly studied. In recent years the genus has been studies by several authors and many new species have been described, conforming previous suspicions that Scorpio maurus Linné, 1758 was a species complex hiding many cryptic species. 

The revision of the Scorpio from Jordan has resulted in a new genus and three new species.

Jordanius Afifeh, Yagmur, Al-Saraireh & Amr, 2024 (new genus)

Jordanius maysaraensis Afifeh, Yagmur, Al-Saraireh & Amr, 2024 (new species)

Scorpio jordanensis Afifeh, Yagmur, Al-Saraireh & Amr, 2024 (new species)

Scorpio wahbehi Afifeh, Yagmur, Al-Saraireh & Amr, 2024 (new species)

Jordanius granulomanus (Al-Saraireh, Yagmur, Afifeh & Amr, 2023) is transferred to the new genus from Scorpio.

In addition, Scorpio propinquus (Simon, 1872) is considered nomen dubium.

The article has an identification key for the Scorpionidae taxa found in Jordan. 

Abstract:
Several new Scorpio populations are studied from various habitats in Jordan, including specimens previously identified as Scorpio kruglovi Birula, 1910 and S. fuscus (Ehrenberg, 1829). A new scorpionid genus, Jordanius gen. n. is described, mainly differentiated from the genus Scorpio Linnaeus, 1758 by the elongation and heavy patterns of granulation of chela manus, and granulated chela fingers. Scorpio granulomanus Al-Saraireh et al., 2023 is transferred to the new genus, and Jordanius maysaraensis gen. et sp. n. is described. Also, Scorpio jordanensis sp. n. and S. wahbehi sp. n. are described. Detailed redescriptions and illustrations of S. palmatus (Ehrenberg, 1828) and S. fuscus (Ehrenberg, 1829) are given. A neotype of S. palmatus from Alexandria, Egypt and a neotype of S. fuscus from Lebanon are designated. A key to the family Scorpionidae in Jordan and comments on dubious or incorrect records from Jordan are provided. Lastly, S. propinquus is suggested as nomen dubium.

Reference:
Afifeh BA, Yagmur EA, Al-Saraireh M, Amr Z. Revision of the genus Scorpio in Jordan, with a description of a new genus and three new species (Scorpiones: Scorpionidae). Euscorpius. 2024(391):1-66. [Open Access]

Family Scorpionidae

Using chemical cues to avoid intraguild predators and to find potential mates

 

It is well known that scorpions can detect and use chemical cues thanks to chemosensitive hairs on the pectins and on part of the pedipalps. Chemical cues can be used to discover and seek out conspecifics for mating, but also to avoid conspecifics or other scorpions that want to eat you (cannibalism is well documented in scorpions, often larger individuals preying on smaller and larger females may also kill and eat potential suitors).

Welton Dionisio-da-Silva and co-workers published earlier this summer a study of the use of chemical cues in the two Brazilian scorpions Bothriurus rochai Mello-Leitão, 1932 (Bothriuridae) and Jaguajir rochae (Borelli, 1910) (Buthidae). They tested the behavioral response to chemical cues from a heterospecific scorpion, and the response of male individuals (B. rochai and J. rochae) to chemical cues from conspecific females.

The study showed that smaller individuals avoided sites with the "smell" of larges individuals, whiles larger predators preferred the sites with the "smell" of smaller scorpions. In addition, males of both species trailed the chemical cues of females. 

According to the authors, this is the first evidence of a scorpion species detecting and hunting a heterospecific scorpion through chemical cues.

Abstract:
Chemical perception is essential among arthropods for mate recognition, prey search, and predator avoidance, especially for solitary predators which are often aggressive. Such mechanisms may be intensified in environments like the Caatinga, a seasonally dry tropical forest in Brazil, characterized by low habitat complexity and high seasonal variation. Thus, we investigated chemical perception between two scorpion species from this environment, involved in intraguild competition. Experiments assessed their response to chemical cues from prey, predators, and potential mates. We use Y-mazes to test the time spent by the scorpions between Y-arms with or without a given substrate-borne chemical cue (site preference) and the number of active individuals during trials (presence of activity). Scorpions’ activity was not influenced by chemical stimuli, although they clearly exhibit site preferences. The smaller predators avoided sites with the larger species’ chemical cues, while the larger predators preferred sites with the smaller species’ cues. Additionally, both species trailed female chemical cues. These findings suggest a dual-oriented arms race where prey and predator modulate their behaviour to avoid and hunt heterospecifics, respectively. This study provides the first evidence of a scorpion using chemical cues to detect a heterospecific scorpion and highlights the importance of this trait in arachnids.

References:
Dionisio-da-Silva W, Araujo Rocha-da-Silva KL, Veloso HMG, DaSilva MB. Hide and seek: chemical cues drive site preference among potential mates and intraguild competitors. Biological Journal of the Linnean Society. 2024:blae058. [Subscription required for full text]

Thanks to Welton Dionisio-da-Silva for sending me their article!

 

Phylogenetic analysis reveal cryptic subspecies of Euscorpius borovaglavaensis in Croatia

 

The genus Euscorpius Thorell, 1876 (Euscorpiidae) from Europa has become notorious for its hidden, cryptic species. A few decades ago this genus consisted of less than 10 species, today the number of taxa is closed to 100.

Martina Podvar and co-workers have publised a phylogenetic and phylogeographic  study of the populations of Euscorpius borovaglavaensis Tropea, 2015 in Croatia. Two distinct lineages were discovered and the population distributed in the northwestern part of the range was given subspecies status.

Euscorpius borovaglavaensis flavus Vignoli, 2024

Abstract:
The European scorpion Euscorpius borovaglavaensis Tropea, 2015 is a morphologically cryptic species that is distinguishable only with difficulty from E. tergestinus (C. L. Koch, 1837). It is distributed in the middle part of the Dinaric Alps chain and along part of the Eastern Adriatic coast, specifically, in Croatia (Middle Dalmatia, Lika karst upland), as well as in the southern part of Bosnia and Herzegovina. The new findings reported here have enhanced our knowledge of its geographic distribution in Croatia. Detailed morphological analyses highlighted the importance of carination in the ventral metasomal segments as morphological traits. Phylogenetic analyses, based on the mitochondrial cytochrome c oxidase subunit I (COI) gene, have revealed the existence of two distinct lineages. One of them, distributed in the northwestern part of the range, is described here as E. b. flavus n. ssp., while the nominal subspecies occurs in the southeastern part. A time-calibrated phylogenetic analysis has established their divergence around 0.9 million years ago, coinciding with the Mid-Pleistocene Transition (MPT) period. In contrast to the nominal subspecies, E. b. flavus n. ssp. exhibits significant phylogeographic structuring, indicating recent isolation events in multiple glacial microrefugia after the initial divergence, followed by a final Holocene dispersal in the northwestern direction deep between the mountain chains.

Reference:
Podnar M, Vignoli V, Tvrtković N. Phylogeographic structuring within recently diverged scorpion species, Euscorpius borovaglavaensis Tropea, 2015 (Scorpiones: Euscorpiidae) in Croatia, with the description of a new subspecies. Natura Croatica: Periodicum Musei Historiae Naturalis Croatici. 2024;33(1):29-52. [Open Access]

Thanks to Valerio and Gerard who both sent me this article!

Family Euscorpiidae

A new paper investigating the phylogeography and evolutionary history of the burrowing scorpion genus Scorpio

 

The genus Scorpio Linnaeus, 1758 (Scorpionidae) was for most of the last century known to have only one species, Scorpio maurus Linnaeus, 1758, which has an impressing distribution ranging from most of North Africa to the eastern parts of the Middle East. 

In the last decades it became clear that Scorpio maurus was a species complex with many hidden species, and today the genus consists of 24 species. However, the taxonomical and phylogentic situation of the genus is challenging, especially because of the lack of reliable morphological characters to distinguish the species and subspecies. Also, several new species have been described without genetic analysis confirming the species status. 

Manel Khammassi and co-workers have recently published a study with the aim of the present study to analyze the phylogenetic relationships and the evolutionary events that promoted diversification within the genus Scorpio. The study revealed twenty distinct lineages forming two geographically separate clades, a Maghrebian clade and a Middle Eastern clade. Most named species were found within the lineages, but additional lineages found are indicating potential new, unnamed species.

Abstract:
The burrowing scorpions of the genus Scorpio Linnaeus, 1758 were considered to be a single polymorphic species, Scorpio maurus Linnaeus, 1758, distributed from West Africa across the Sahel and the Saharan highlands through the Maghreb and the Middle East, to Iran. After various revisions, the complex was treated as including 18 species and seven subspecies. Five additional new Scorpio species were recently described. However, doubts remain regarding the validity of these taxa due to the lack of reliable characters and the lack of genetic data for many species. The aim of the present study was to analyze the phylogenetic relationships and the evolutionary events that promoted diversification within the genus. Phylogenetic analyses were performed using 633 base pairs of the mitochondrial COI gene from 51 individuals collected in Tunisia, Morocco, and Egypt, combined with 74 previously published sequence data. Phylogenetic analyses revealed twenty distinct lineages forming two geographically separate clades, a Maghrebian clade and a Middle Eastern clade. Although most named species formed distinct lineages, various additional lineages were identified, highlighting potential unnamed species. Divergence time estimates indicate that the division within the genus Scorpio began during the Mid-Miocene, a period characterized by tectonic events coupled with climatic oscillations. Further differentiation occurred during the Miocene-Pliocene transition when climatic fluctuations resumed and the Mediterranean became increasingly arid. Speciation within the genus Scorpio may have been driven by the expansion of the savannas and Sahara Desert, the associated reduction of a once widespread rainforest into numerous micro-refugia in the mountains of the Mediterranean region, and by adaptation to these new habitats

Reference:
Khammassi M, Nouira S, Badry A, Sadine SE, Harris DJ. Phylogeography and evolutionary history of the burrowing scorpion genus Scorpio Linnaeus, 1758 (Scorpiones: Scorpionidae) in the Mediterranean Basin. Organisms Diversity & Evolution. 2024:1-18. [Subscritpion required for full text]

Family Scorpionidae

A study on the relative efficacy of three antivenoms against medically significant Centruroides species from Mexico

 

Mexico is a hot spot for medical important scorpions and at least 21 species from the Centruroides Marx, 1890 (Buthidae) genus cause a large number of serious envenomations every year. Good treatment options is important and using antivenom is one of the most important tool.

Sam Campbell and co-workers have recently published a study looking into the ability of three  antivenoms to neutralize the activity of the venoms of several Centruroides species. One important result from this study is that the truly “broad” neutralization capacity of the antivenoms can be questioned as there were variations in the neutralization of several medical important Centruroides species (even though the venom of these were included in the antivenoms).

The author also stress the importance of proper laboratory studies and methods for studying the effects of antivenom candidates.

Abstract:
In this study, we report the innovative application of whole-cell patch-clamp electrophysiology in assessing broad-spectrum neutralisation by three different antivenoms, of venoms from the medically significant scorpion genus Centruroides. Envenomations by as many as 21 species from the Centruroides genus result in up to 300,000 envenomations per year in Mexico, which poses significant and potentially life-threatening pathophysiology. We first evaluated the in vitro manifestation of envenomation against two human voltage-gated sodium (hNaV) channel subtypes: hNaV1.4 and hNaV1.5, which are primarily expressed in skeletal muscles and cardiomyocytes, respectively. The neutralisation of venom activity was then characterised for three different antivenoms using a direct competition model against the more potent target, hNaV1.4. While broad-spectrum neutralisation was identified, variation in neutralisation arose for Centruroides elegans, C. limpidus, C. noxius and C. suffusus venoms, despite the presence of a number of these venoms within the immunising mixture. This raises questions regarding the truly “broad” neutralisation capacity of the antivenoms. This study not only extends previous validation of the in vitro investigation of antivenom efficacy utilising the whole-cell patch-clamp technique but also underscores the potential of this animal-free model in exploring cross-reactivity, experimental scalability, and most importantly, informing clinical management practices regarding the administration of antivenom in Mexico.

Reference:
Campbell SID, Chow CY, Neri-Castro E, Alagón A, Gómez A, Soria R, et al. Taking the sting out of scorpions: Electrophysiological investigation of the relative efficacy of three antivenoms against medically significant Centruroides species. Comparative Biochemistry and Physiology Part C: Toxicology & Pharmacology. 2024;283:109977. [Open Access]

Thanks to Jeroen Kooijman for informing me about this article!

New information about medical important Tityus species in Brazilian Amazonas

 

It is well known that several species of Tityus C. L. Koch, 1836 (Buthidae) causes death and serious morbidity in Brazil. Most infamous among these are probably Tityus serrulatus Lutz & Mello, 1922, but also other species cause serious sting incidents in humans in Brazil and the Amazon region, though reports are often sporadic. More studies are necessary to learn more about the effects of other Tityus species in the region.

Jonas Martins and co-workers published previously this summer a study on the systemic effects caused by the venom of the Amazonian scorpions Tityus dinizi Lourenço, 1997 and T. strandi Werner, 1939 using a murine model. The results indicates that both species may have a medical importance for humans, T. strandi being the most potent of the two. 

This information is important both for preventive measures and for therapeutic choices when dealing with scorpion stings caused by Amazonian scorpions.

Abstract:
The Brazilian Amazon is home to a rich fauna of scorpion species of medical importance, some of them still poorly characterized regarding their biological actions and range of clinical symptoms after envenoming. The Amazonian scorpion species Tityus strandi and Tityus dinizi constitute some of the scorpions in this group, with few studies in the literature regarding their systemic repercussions. In the present study, we characterized the clinical, inflammatory, and histopathological manifestations of T. strandi and T. dinizi envenoming in a murine model using Balb/c mice. The results show a robust clinical response based on clinical score, hyperglycemia, leukocytosis, increased cytokines, and histopathological changes in the kidneys and lungs. Tityus strandi envenomed mice presented more prominent clinical manifestations when compared to Tityus dinizi, pointing to the relevance of this species in the medical scenario, with both species inducing hyperglycemia, leukocytosis, increased cytokine production in the peritoneal lavage, increased inflammatory infiltrate in the lungs, and acute tubular necrosis after T. strandi envenoming. The results presented in this research can help to understand the systemic manifestations of scorpion accidents in humans caused by the target species of the study and point out therapeutic strategies in cases of scorpionism in remote regions of the Amazon.

Reference:
Martins JG, Reis MB, Zuanazzi BA, Bordon KdCF, Zoccal KF, de Lima Procópio RE, et al. Clinical outcomes in a murine model after envenoming by the Amazonian scorpions Tityus strandi and Tityus dinizi. Toxicon. 2024;246:107797. [Subscription required for full text]

Thanks to Jonas Martins for sending me their article!