Sensory structures in the aculeus part of the scorpion's tail

 

It is well known that scorpions can detect and use chemical cues and substrate vibrations thanks to chemosensitive hairs and other structures on the pectins and on part of the pedipalps. In a recent article, Melek Erdek and Ersen Yagmur describe and discuss potential sensory structures found in the scorpions' aculeus. Aculeus is the outer part of the telson where the stinger starts and it is covered with aculear peg sensilla and pore holes. 

Abstract:
The scorpion telson is composed of a bulbous shaped base with two venom glands and an aculeus with two venom channels that open to the exterior. The cuticular surface of the aculeus is covered with aculear peg sensilla and pore holes. These sensillar pegs are located on the aculeus surface of the telson and function as contact chemoreceptors. Data on aculear peg sensilla are presented from both parvorders, four families, 15 genera and 15 species of extant scorpions. Although all aculear peg sensilla have a similar structure in all species and sexes in terms of their general morphology, their location and frequency on the surface of the aculeus cuticle varies. The shape of these sensilla is similar in all species, and the distribution density on the cuticle surface differs from species to species. The single slit sensilla were observed at various intervals and numbers in the aculeus-bulb connection area of the telson.

Reference:
Erdek M, Yagmur EA. A comprehensive evaluation of the aculear sensory structures in scorpions (Arachnida: Scorpiones). Arthropoda Selecta. 2024;33(3):355-74. [Open Access]

Thanks to Ersen for sending me their article!

A new species of Tityus from Colombia

 

Leo Laborieux just published an article describing a new species of Tityus C. L. Koch, 1836 (Buthidae) from the Cordillera Oriental in Colombia.

Tityus icarus Laborieux, 2024

PS! Check out the the explanation (etymology) for the name chosen for this new species! :)

Abstract:
A new species belonging to the genus Tityus (Atreus) (family Buthidae, C. L. Koch, 1837) is described from the Colombian Cordillera Oriental on the basis of three specimens collected in La Vega (Cundinamarca department). Specimens of Tityus (Atreus) icarus sp. n. were collected in a patch of medium-altitude broadleaf rainforest, 1350 a.s.l. The new species shares affinities with T. (Atreus) antioquensis Lourenço & Otero-Patiño, 1998, and T. (Atreus) nematochirus Mello-Leitão, 1940, but can be readily distinguished from these two taxa based on morphometric differences and a combination of several characters. The new species is the 229th described in the genus.

Reference:
Laborieux L. A new species of Tityus Koch, 1836 (Scorpiones: Buthidae), from the Cordillera Oriental (Colombia). Faunitaxys. 2024;12(41):1-9. [Open Access]

Thanks to Gerard Dupre for sending me this article!

Family Buthidae

Activity patterns of the medical important scorpion Tityus serrulatus in an urban habitat in Brazil

 

Tityus serrulatus Lutz & Mello, 1922 (Buthidae) is probably the most medical important scorpion in Brazil and South America and one of the main reasons for this is the species' opportunistic life style and its adaption to urban habitats.  

José Brites-Neto and co-workers have recently published a study of the activity patterns and reproduction of a population of Tityus serrulatus in a urban habitat in the state of São Paulo in Brazil (in a cemetery). Increased knowledge of this medical important species' behavior and activity is important for those working to prevent scorpion envenomations when humans and scorpions share the same habitat.

Abstract:
Tityus serrulatus Lutz & Mello (Scorpiones: Buthidae) is a scorpion endemic to Brazil adapted to synanthropic life, colonising and proliferating in the most populous urban areas in the country. Here, we evaluated its activity pattern in an urban cemetery in the municipality of Americana, state of S˜ao Paulo, Brazil. Additionally, we tested the effects of species reproduction and climatic seasons on the activity pattern. The Saudade Municipal Cemetery was sampled between 17:00 and 22:00 h during 455 nights from April 2006 to December 2013. The circular mean and the peak of activity were quantified for the total number of specimens, and for specimens with and without broods. Activity patterns were inferred using a rosette diagram. Circular analysis of variance was used to investigate if activity patterns changed across climatic seasons (wet and dry seasons). A total of 25,969 records (467 specimens with broods) were obtained in the field. The circular mean varied between 19:44 and 19:48 h, and the peak of activity occurred between 18:00 and 20:00 h for all groups. Peaks of activity differed from that recorded under laboratory conditions (between 21:00 and 23:00 h). Activity patterns did not differ for specimens with broods, suggesting that the reproductive condition does not alter the species activity pattern. The activity pattern differed between wet and dry seasons for all specimens and specimens without broods, but differences were small and probably biologically irrelevant, probably because the species tolerates a wide variation in abiotic conditions. Deepening the knowledge of the behaviour activity of T. serrulatus can have practical applications for health surveillance agencies, aiming to increase the effectiveness of scorpion control in urban areas.

Reference:
Brites-Neto J, Willmer JNG, Delciellos AC. Activity pattern of Tityus serrulatus (Scorpiones: Buthidae) in an urban area in the state of Sao Paulo, Brazil. Med Vet Entomol. 2024. [Subscription required full text]

Antibiotic-producing bacteria discovered in tissue from the giant sand scorpion, Smeringurus mesaensis

 

As most of you know, there is an increasing and worrying number of treatment resistant bacteria in the world. It is probably safe to say that we are now in an antibiotic resistance crisis. The venom of scorpions have for several years provided several candidates for medical treatments (e.g. Chlorotoxin from Leiurus quinquestriatus (Ehrenberg, 1828) (Buthidae)), but a recent paper suggests that scorpions can contribute with more than their venom.

In a recent article, Atkinson and co-workers present the discovery of antibiotic-producing bacteria in tissue samples from the giant sand scorpion, Smeringurus mesaensis (Stahnke, 1957) (Vaejovidae). It is important to note that this is results from laboratory studies and more research is necessary before the antibiotic effect can be confirmed for humans. But the study opens up the exciting possibility that scorpion tissues can provide a new source of antimicrobial molecules in the war against antibiotic resistance. 

Abstract:
Antibiotic resistance is a global health crisis. Our current arsenal of antibiotics—drugs meant to kill bacteria and stop their population growth—is becoming less effective at treating bacterial infections as resistant bacteria emerge, fueling the dire need to discover new antibiotics. Most antibiotics in use today have been discovered from bacteria. To increase the chances of finding potentially novel antibiotic molecules, we studied the relatively unexplored microbial environment of scorpion tissues, using the giant sand scorpion, Smeringurus mesaensis (Stahnke, 1957). Bacterial symbionts were isolated and cultured from the mesosoma and metasoma, and isolates were tested in a functional assay for production of antibiotics. Under the culture conditions utilized, most scorpion-derived bacteria were from the phyla of Firmicutes, Proteobacteria and Actinobacteria. Fifty five percent of the clonal isolates tested produced antibiotics, with most being Bacillus species. None of the bacterial conditioned media were cytotoxic to mammalian cells. This study suggests scorpion tissues may provide a rich source of antimicrobial molecules to help combat the antibiotic resistance crisis.

Reference:
Atkinson L, Shimwell C, Lucin KM, Graham MR, Murdoch B. Antibiotic-producing bacteria isolated from the giant sand scorpion, Smeringurus mesaensis (Scorpiones: Vaejovidae). The Journal of Arachnology. 2024;52(2):116-26. [Subscription required for full text]

Thanks to Matt Simon for informing me about this article!

Molecular study of medical important Hemiscorpius species from Iran

 

Correct identification of medical important scorpions is very important to be able to provide optimal treatment. Many species are morphological similar and this will make correct identification difficult. This is the case with many species of Hemiscorpius  Peters, 1861 (Hemiscorpiidae) in Iran. 

Shahi and Barahoei have recently published a molecular study on the Hemiscorpius fauna in the Hormozgan province in southern Iran. The study confirms the validity of the following three species in the genus:

Hemiscorpius acanthocercus Monod & Lourenço, 2005
Hemiscorpius enischnochela Monod & Lourenço, 2005
Hemiscorpius lepturus Peters, 1861

This is important information as the available antivenom for this genus do not work optimal inn all cases and this might be because there are different species involved. 

Abstract:
Three species of Hemiscorpius were identified in Hormozgan province, for which the available antivenoms lack the efficacy required for treating patients. Consequently, an exact identification of the existing species was deemed necessary as the first step in managing treatment procedures. Considering the morphological similarities among the species, the aim of this research was the molecular study of the samples to accurately identify the species. Hemiscorpius specimens were collected from various locations in Hormozgan province between 2021 to 2023. The Cytochrome c oxidase subunit I gene was amplified and sequenced. Four sequences were obtained from Hemiscorpius specimens collected from Hormozgan province, and three sequences were sourced from the NCBI for analysis. Bayesian inference and Maximum likelihood phylogenetic trees showed similar results, positioning the base of Hemiscorpius enischnochela tree as an older species and Hemiscorpius lepturus adjacent to Hemiscorpius acanthocercus, identified as the newest species at the tree's tip. The results confirmed the validity of three species, namely H. acanthocercus, H. enischnochela, and H. lepturus. Hemiscorpius acanthocercus and H. lepturus are known for having dangerous venom for humans with reported deaths due to their stings. Considering the importance of the members of this genus from the medical point of view, a comprehensive examination of all species is imperative.

Reference:
Shahi M, Barahoei H. Molecular study of Hemiscorpius Peters (Scorpiones: Hemiscorpiidae) in Hormozgan province, South of Iran. Arch Razi Inst. 2024;79(1):211-7. [Open Access]

Family Hemiscorpiidae

Scorpion taxidermy - How should you preserve scorpions for research and exhibition

 

Victoria Trang published a very useful article this weekend on scorpion taxidermy. Preserving scorpion specimens in a correct and durable way is essential both for taxonomy science and for other purposes like exhibitions etc. 

Victoria discusses the different techniques of taxidermy and propose guidance for optimal preservation depending on the purpose of the specimen in question. This article should be of great interest both for professionals and scorpion enthusiasts that want to preserve their scorpions after their death.

Abstract:
Scorpions hold a renowned status as iconic creatures across numerous cultures in the world. Traditionally preserved as desiccated specimens for educational purposes, they have been exhibited in museums and pedagogic collections, serving as concrete epistemological conduits for public education on biodiversity. However, these specimens frequently lack meticulous organization, potentially misrepresenting the animals’ ethological characteristics. This brief article aims to offer paradigmatic guidance for taxidermy of scorpions, ensuring a more accurate depiction of their in vivo habitus, achievable through the use of readily obtainable tools and undemanding techniques.

Reference:
Tang V. Methodologies for dry fixation and taxidermy of education-oriented scorpion specimens. Euscorpius. 2024(395):1-24. [Open Access]