Common toxin components among different Tityus species in the Amazon region may lead to a common therapeutic strategy

 

Scorpionism is a major problem in many parts of the world, and for the Amazon Region in South America several Tityus C. L. Koch, 1836 species (Buthidae) are known to cause severe morbidity or even deaths. The problem is that there is no effective antivenom currently available in this region.

Identifying the different toxin components of the venom of different Tityus species may lead to the development of new therapeutics.Yan Kalapothakis and co-workers have recently published a study analysing the venom of the medical important species Tityus cisandinus Lourenço & Ythier, 2017 and comparing it to the venom of another medical imprtant species T. obscurus (Gervais, 1843).

Interestingly, they found a high similarity between T. cisandinus and T. obscurus venoms. This is important knowledge that can be used to create a "common therapeutic strategy (i.e production of a region-specific antivenom) to tackle the increasing burden of scorpionism in Amazonia" [Adolfo Borges, personal communication].

Abstract:
Tityus cisandinus, a neglected medically important scorpion in Ecuadorian and Peruvian Amazonia, belongs to a complex of species related to the eastern Amazon endemic Tityus obscurus, spanning a distribution of ca. 4000 km. Despite high morbidity and mortality rates, no effective scorpion antivenom is currently available in the Amazon region. Knowledge of the structural/functional relationships between T. cisandinus venom components and those from related Amazonian species is crucial for designing region-specific therapeutic antivenoms. In this work, we carried out the first venom gland transcriptomic study of an Amazonian scorpion outside Brazil, T. cisandinus. We also fingerprinted its total venom through MALDI-TOF MS, which supported our transcriptomic findings. We identified and calculated the expression level of 94 components: 60 toxins, 25 metalloproteases, five disulfide isomerases, three amidating enzymes, one hyaluronidase, and also uncovered transcripts encoding novel lipolytic beta subunits produced by New World buthid scorpions. This study demonstrates the high similarity between T. cisandinus and T. obscurus venoms, reinforcing the existence of a neglected complex of genetically and toxinologically related Amazonian scorpions of medical importance. Finally, we demonstrated the low recognition of currently available therapeutic sera against T. cisandinus and T. obscurus venoms, and concluded that these should be improved to protect against envenomation by Amazonian Tityus spp.

Reference:
Kalapothakis Y, Miranda K, Molina DAM, Conceição I, Larangote D, Op den Camp HJM, et al. An overview of Tityus cisandinus scorpion venom: Transcriptome and mass fingerprinting reveal conserved toxin homologs across the Amazon region and novel lipolytic components. Int J Biol Macromol. 2022. [Subscritpion required for full text]

Thanks to Adolfo Borges for informing me about this article!

Paruroctonus marksi is most active when it is warm and humid

 

Scorpion surface activity is influenced by several factors, both biotic (e.g. prey or mate availability or predator risk) and abiotic (e.g. weather or illumation). Zia Nisani and co--workers have recently published a study on seasonal variations of Paruroctonus marksi Haradon, 1984 (Vaejovidae) activity in the Mojave Desert in California, US.

Their main finding was that the scorpions were mostly active in warm and humid nights, but that soil temperature also seemed to have a small impact on the activity.

Abstract:
Many environmental factors may influence the activity pattern of scorpions in arid ecosystems. We investigated the seasonal variations of Paruroctonus marksi scorpion activity in the Mojave Desert (California, USA). Black light surveys were carried out within two 100 ×100 m plots from August 2017 to September 2018. The majority (85%) of scorpions were found in open areas compared with being in vegetation. The presence of P. marksi was positively correlated with both water vapor pressure and soil temperature, while moon illumination had no significant effect on P. marksi foraging behavior. Scorpions might be using humidity as an indicator of prey abundance and since they are not visual hunters, and moonlight does not affect their surface activity possibly due to lack of visual hunters in the study site.

Reference:
Nisani Z, Frederick D, Garcia-Plascencia A, Lopez D, Miller R, Trinh-Nguyen L. Influence of environmental factors on surface activity of Paruroctonus marksi (Scorpiones: Vaejovidae) in the Mojave Desert. Euscorpius. 2022(364):1-5. [Open Access]

A new species of Hottentotta from Iran

 

Mohammad Moradi and co-workers have recently described a new species of Hottentotta Birula, 1908 (Buthidae) from Khuzestan Province in Iran.

Hottentotta pooyani Moradi, Yagmur & Akbari, 2022

Abstract:
A new species, Hottentotta pooyani sp. nov. is described and illustrated using two female specimens collected from the Khuzestan Province in Iran. This species is compared with the closely species including H. khoozestanus Navidpour, Kovařík, Soleglad & Fet, 2008; H. pellucidus Lowe, 2010 and H. saxinatans Lowe, 2010 that were previously described in Iran and Oman.

Reference:
Moradi M, Yagmur EA, Akbari A. Hottentotta Pooyani sp. nov. (Scorpiones, Buthidae) from the Khuzestan Province, Iran. Bull Iraq nat Hist Mus. 2022;17(2):251-66. [Open Access]

Thanks to Ersen for sending me their article!

Family Buthidae

Scorpion mimicry observed in a Brazilian gecko

 

Avoid being killed and eaten is one of the central tasks for most animals. There is a host of anti-predator strategies around and one popular strategy is to mimic the look and/or the behavior of another dangerous animal (Batesian mimicry).  

Scorpions can be classified as a dangerous animal because of the venomous sting. They are also very characteristic with their tail with a stinger clearly displayed above the body. So it is not surprising that other animals may try to mimick scorpions in appearance and behavior to scare off potential predator. E. g., this can be seen in many stick insects where they curve the posterior part of their body above the rest of the body mimicking a scorpion's tail.

Matheus Feitosa and co-workers have recently published an article describing scorpion mimicry in the sphaerodactylid gecko Coleodactylus meridionalis (Boulenger, 1888) from Brazil, that share their habitat with Tityus pusillus Pocock, 1893 (Buthidae).

Abstract:
No abstract.

Reference:
Feitosa MLB, da Silva Júnior AO, da Justa Ximenes RE, Lins AHA, Moura GJ, de Araújo Lira AF. Scorpion mimicry behavior in Coleodactylus meridionalis (Squamata: Sphaerodactylidae) in the northeastern Atlantic forest. Herpetology Notes. 2022;15:829-31. [Open Access]

A new species of Tarsoporosus from the Colombian Caribbean region

 

Edwin Bedoya-Roqueme and André F.A. Lira have described a new species of Tarsoporosus Francke, 1978 (Diplocentridae) from the Colombian Caribbean region.

Tarsoporosus tizopedrosoi Bedoya-Roqueme & Lira, 2022

The total number of species in the genus is now six and the article has an identification key for all known species.

Abstract:
We describe the novel species Tarsoporosus tizopedrosoi sp. n., based on two individuals collected from a humid forest in the south of Córdoba in the Colombian Caribbean region. This new species is distinguished by its smooth, shiny surface without granules, pectinal tooth counts, telotarsi spiniform macrosetae formula, and measurements of its morphological structures. A distribution map, ecological comments, and taxonomic key are described.

Reference:
Bedoya-Roqueme E, Lira AFA. A new Tarsoporosus Francke, 1978 (Scorpiones: Diplocentridae) species from the south of the Cordoba department in the Colombian Caribbean region. Revista Iberica de Arachnologia. 2022(41).

Thanks to Andre Lira for sending me their new article!

Family Diplocentridae

A new species of Scorpiops from China

 

Heyu Lv and Zhiyong Di have studied new materials of Scorpiops Peters, 1861 (Scorpiopidae) from China and have published a few taxonomical updates.

Scorpiops lourencoi Lv & Di, 2022 (New species from China)

Scorpiops atomatus Qi, Zhu & Lourenço, 2005 (restored from synonymy with Scorpiops tibetanus Hirst, 1911)

Scorpiops tibetanus Hirst, 1911 is redescribed.

The article also have an updated identification key for the Scorpiops species of China.

Abstract:
Scorpiops lourencoi sp. nov. is described from Shigatse, Xizang. Scorpiops atomatus Qi, Zhu & Lourenço, 2005 and Scorpiops pococki Qi, Zhu & Lourenço, 2005 were synonymized by Kovařík et al. (2020) as two junior synonyms of Scorpiops tibetanus Hirst, 1911 but based on several field surveys in Xizang in recent years, and a careful survey of the literature, S. atomatus is reaffirmed as a valid species and S. tibetanus is redescribed, both based on newly collected specimens. This brings the total number of species of Scorpiops recorded in China to 32.

Reference:
Lv H-Y, Di Z-Y. Scorpiops lourencoi sp. nov., the revalidation of Scorpiops atomatus Qi, Zhu & Lourenço, 2005, and the redescription of Scorpiops tibetanus Hirst, 1911 (Scorpiones, Scorpiopidae) from China. ZooKeys. 2022(1132):189-214. [Open Access]

Thanks to Gerard Dupre and Matt Simon for sending me this article!

Family Scorpiopidae