New book on the biology of neotropical scorpions

 

André Felipe de Araujo Lira and Edmundo González-Santillán are editors for a brand new book on the biology of neotropical scorpions. This book contains a comprehensive review of all aspects of the scorpions in the important neotropical region, which is known both for its high biodiversity and the high number of medical important species.

About the book [from the publisher]

The Biology of Neotropical Scorpions focuses on comprehensive aspects of scorpions of the Neotropical region, such as public health to biogeographic history. This innovative book is devoted to tackling that lack of knowledge and bringing together a bundle of studies to offer students, researchers, and professionals a comprehensive background to start their research with scorpions as model organisms.

Since 1990 the study of scorpions thrived following the tradition focusing on the Palearctic and Neartic fauna, leaving behind ancient and important scorpion fauna localised in the Neotropics. The Neotropical region encompasses the tropical areas from South America to central Mexico, including the Antilles, comprising different biomes in their extension, such as deserts, dry forests, savannas, mountain ranges, and rainforests. These myriad environments influenced scorpions from their venom composition, morphology, and their human interactions.

Many researchers from different areas and countries have generated a growing piece of information about Neotropical scorpions, but this still is fragmentary. This book innovates in the biology of scorpion fluorescence, chromosomal and molecular genetics, conservation ecology, and ethnobiology of scorpions from the perspective of traditional medicine.

Table of content:

1 What Are the Neotropical Scorpions? . . . . . . . . . . . . . . . . . . . . . . . . . . 1
André Felipe de Araujo Lira
2 Allometry and the Evolution of Sexual Size Dimorphism
in Scorpions: Insights from Neotropical Species . . . . . . . . . . . . . . . . . 13
Stênio Ítalo Araújo Foerster
3 Mating or Not? Reproductive Aspects of Sexual Reproduction
and Parthenogenesis in Neotropical Scorpions . . . . . . . . . . . . . . . . . . 31
Gracielle de Fátima Braga-Pereira and André Felipe de Araujo Lira
4 Luminescence and Other Optical Characteristics of Scorpion’s
Exoskeleton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
Daniel López-Cabrera, Gabriel Ramos-Ortiz,
Montserrat G. Rivera-Ortiz, Edmundo González-Santillán,
and Rafael Espinosa-Luna
5 Diversity, Taxonomy, and Distribution of Neotropical Scorpions . . . 69
Edmundo González-Santillán, José Antonio Ochoa,
and Andrés Alejandro Ojanguren-Afilastro
6 Advances in the Phylogenomic Relationships of Neotropical
Scorpions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 123
Carlos E. Santibáñez-López and Prashant P. Sharma
7 Fossil Scorpions, with a Focus on the Neotropical Species . . . . . . . . . 151
Jason A. Dunlop
8 Biogeography of Neotropical Scorpions: An Overview . . . . . . . . . . . . 179
Adriano Medeiros DeSouza
and Alessandra Rodrigues Santos de Andrade
9 Subterranean and Troglomorphic Scorpions from the Neotropics . . . 199
Edmundo González-Santillán, Javier Blasco-Aróstegui,
and Jairo A. Moreno-González 
10 Functional Morphology of Predatory and Defensive Behaviour
in Neotropical Scorpions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 225
Yuri Simone
11 Sampling Techniques for Scorpions . . . . . . . . . . . . . . . . . . . . . . . . . . . 247
Nancy Lo-Man-Hung and Andria de Paula Santos-da-Silva
12 Cytogenetics of Neotropical Scorpions . . . . . . . . . . . . . . . . . . . . . . . . . 261
Bruno Rafael Ribeiro de Almeida, Jonas Gama Martins,
and Renata Coelho Rodrigues Noronha
13 Neotropical Scorpions as Useful Models for Ecological Studies . . . . . 289
André Felipe de Araujo Lira
14 Traditional Treatment of Scorpion Stings in the Neotropics . . . . . . . 307
Jonas Gama Martins, Bruno Rafael Ribeiro de Almeida,
Pedro Pereira de Oliveira Pardal,
and Rudi Emerson de Lima Procópio
15 Neotropical Scorpion Venom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 325
Juana María Jiménez-Vargas, Jimena Isaias Cid-Uribe,
and Rita Restano-Cassulini
16 Scorpionism in Neotropics: Public Health Issues and Prevention . . . 353
Clara Guerra-Duarte and Ana Luiza Bittencourt Paiva
17 Managing Scorpionism: Envenomation, Diagnostics,
and Therapeutic Approaches . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 389
Manuela B. Pucca, Isabela C. dos Santos, and Felipe A. Cerni
18 Perspectives on Biology and Interactions with Humans
of Neotropical Scorpions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 403
Edmundo González-Santillán
Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 407

Reference:
Lira AFA, Gonzalez-Santillan E, editors. The Biology of Neotropical Scorpions. From Taxonomy and Genetics to Ecology and Ethnobiology: Springer; 2026. [The book is available in an electronic version or in a printed version, but both require payment or subscription]

Do hot temperatures cause hot tempered scorpions?

 

Scorpions are dependent on the temperatures in its environment to regulate their body temperatures (being ectothermic) and they will probably also have an effect on scorpion behavior. Scorpions use their sting and venom in prey capture and defense. 

Zia Nisani and co-workers have recently published a study looking into if and how different temperatures impact stinging behavior in Hadurus obscurus Williams, 1970 (Hadruridae). They tested how different temperatures impacted the defensive sting response and also the prey capture behavior at three different temperatures.

Scorpions with higher temperatures were faster to sting and required less provocation before stinging. In addition, "hotter" scorpions were quicker to catch prey and succeed with it. A physiological explanation for these results is probably that increased temperatures will increase muscle performance and metabolic rate. 

Abstract:
Scorpions employ their stinging mechanism both for defense and predation, and being ectothermic, temperature influences their physiology and behavior. As such, we hypothesized that temperature both affects defensive stinging and prey-capture behavior in scorpions. We tested the effects of body temperature on these behaviors in the desert hairy scorpion, Hadrurus obscurus Williams, 1970. In the first experiment, scorpions were placed in temperature-controlled chambers with either high (26-28°C) or low (21-22°C) temperatures and probed to elicit a defensive sting. We recorded the reaction time and the number of probes needed to elicit a sting. In the second experiment, we observed and recorded prey capture behavior at three different temperatures (21, 29, and 33°C). Scorpions with higher body temperatures had faster defensive reaction times and required fewer probes to elicit a sting. Furthermore, at a higher temperature, scorpions were more likely to attempt and succeed in prey capture, but temperature did not seem to affect post-capture stinging behavior. As the temperature rises, increasing muscle performance and metabolic rate in ectotherms, it may cause an increase in prey capture attempts and faster reaction times, as observed in our experiment. These results support our hypothesis that both defensive and predatory behavior in H. obscurus is affected by temperature, allowing more insight into scorpion thermal ecology.

Reference:
Nisani Z, Bennett M, Enriquez A, Iniquez M, Martinez Rios E, Stone B. Effect of temperature on the defensive and predatory behavior of the scorpion Hadrurus obscurus (Scorpiones: Hadruridae). Euscorpius. 2026;2026(433):1–9. [Open Access]

Microbiota discovered in the venom of two scorpion species

 

There is a great research interest in scorpion venom these days, especially the hunt for toxins and other elements that can be used in medical research. The scorpion venom is known to contain a cocktail of peptids, enzymes and other inorganic and organic compounds, but it has been believed that the venom has been sterile venom it comes to bacteria and other microbiota.

Barbara Murdoch and co-workers recently published an article revealing the presence of several bacteria in the venom of the scorpions Paruoctonus becki (Gertsch & Allred, 1965) (Vaejovidae) and Anuroctonus phaiodactylus (Wood, 1863) (Anuroctonidae). This is the first report of microbiota in scorpion venom.

Matt Simon, who informed me about this article, noticed several interesting facts in this article. Firstly, many of the observed bacteria are known to have evolved for extreme conditions, Secondly, one of the observed genera (Nocardioides) is known to produce antimicrobial compounds. The latter is especially interesting, as it may suggest that antibiotic properties of scorpion venom may not be caused by the scorpion itself, but by bacteria in the venom.

Abstract:
With low nutrient availability and presence of numerous antimicrobial peptides, animal venoms have been traditionally considered to be harsh sterile environments that lack bacteria. Contrary to this assumption, recent studies of animal venom and venom-producing tissues have revealed the presence of diverse microbial communities, warranting further studies of potential microbiota in other venomous animals. In this study we used 16S rRNA amplicon sequencing to elucidate whether scorpion venom contained bacteria, to characterize the bacterial communities, and determine if venom microbiomes differed across geologically complex geographic locations. Our study compares the venom microbiome of two scorpion species, sampled from sites in the Mojave and Great Basin deserts, Paruoctonus becki (family of Vaejovidae) and Anuroctonus phaiodactylus (family of Anuroctonidae), and represents the first assessment of microbial diversity ever conducted using the venom secretion itself, rather than the venom-producing organ and its surrounding tissues.

Reference:
Murdoch B, Kleinschmit AJ, Santibáñez-López CE, Graham MR. Microbiota discovered in scorpion venom. PLoS One. 2026;21(1):e0328427. [Open Access]

Thanks to Matt Simon for informing me about this papers and for his comments! 

A redescription of Centruroides infamatus and the description of a new species from Mexico

 

Happy New Year! 

Javier Ponce-Saavedra and co-workers recently published an article with a redescription of Centruroides infamatus (C.L. Koch, 1844) from Mexico. The study also identify a new species that previously were considered a population of this species from the municipality of Jalpa in the southern region of the state of Zacatecas, Mexico.

Centruroides rommeli Ponce-Saavedra, Linares-Guillen, Quijano-Ravell & Chassin-Noria, 2025

The article is in Spanish. 

Abstract:
Centruroides infamatus (C.L. Koch) is redescribed based on individuals obtained from a population from the León, Guanajuato region, in central Mexico. The species is redescribed because in the original description only the country is mentioned as the type locality with no further details. Also, Centruroides rommeli sp. nov. is described based on individuals obtained from a population of scorpions from Jalpa, municipality of Jalpa in the southern region of the state of Zacatecas, Mexico. This species is placed in the subgroup "infamatus" as part of the "striped" scorpions. Morphological comparisons are carried out with C. suffusus (Pocock) and C. vittatus (Say), both species that belong to the same subgroup talso recorded in Zacatecas. Additionally, is included the redescription of C. infamatus, because the population of the new species was previously identified with this specific name. Centruroides rommeli sp. nov. is sympatric with Mesomexovis spadix (Hoffmann), scorpions of the Vaejovidae family.

Reference:
Ponce J, Linares Guillén JW, Quijano-Ravell A, Chassin-Noria O. Redescription of Centruroides infamatus (Scorpiones: Buthidae) and description of a new species of “striped” scorpion of the “infamatus” subgroup from north-central México. Revista de la Sociedad Entomologica Argentina. 2025;84(4):e0409. [Full text supplied by authors]

Family Buthidae 

A new species of Mesomexovis from Mexico

 

André Felipe de Araujo Lira and González-Santillán recently identified a new species of Mesomexovis Gonzalez-Santillan & Prendini, 2013 (Vaejovidae) from Estación de Biología Chamela, Jalisco in Mexico  while studying the scorpion fauna in this area.

Mesomexovis caxcan Lira & Gonzalez-Santillan, 2025

The article also has an identification key for the scorpions in this area.

Abstract:
Mesomexovis Gonzalez-Santillan & Prendini, 2013 is a scorpion genus of the Vaejovidae family that comprises seven species, all endemic to Mexico. The present study describes a new species from Estación de Biología Chamela, Jalisco, related to M. occidentalis (Hoffmann, 1931), M. atenango (Francke & Gonzalez-Santillan, 2006), and M. subcristatus (Pocock, 1898). Mesomexovis caxcan sp. nov. differs from these species in several respects. Firstly, the carinae of the pedipalp chelae are vestigial. Secondly, the ventral lateral carinae of metasomal segments I–IV are granular, and the ventral submedian carinae of segments I–IV are costate to granular. A microstructural separation between the subex and the basal carina of the capsular area of the hemispermatophore is described for the first time. Mesomexovis caxcan sp. nov. represents the eighth species of the genus and the fifth reported in the Estación de Biología Chamela. The other scorpions identified in this location are Centruroides chamela Ponce Saavedra & Francke, 2011, C. elegans (Thorell, 1876) (Buthidae), Konetontli chamelaensis (Williams, 1986), and Thorellius intrepidus (Thorell, 1876) (Vaejovidae).

Reference:
Lira AFdA, Gonzalez-Santillan E. The scorpions of the Estación de Biología Chamela, Jalisco, Mexico with the description of a new species of Mesomexovis (Scorpiones, Vaejovidae) and an identification key. ZooKeys. 2025(1243):241–67. [Open Access]

Thanks to Gerard Dupre and Matt Simon for informing me about this new species!

Family Vaejovidae

Sting use in Centruroides sculpturatus in a defensive context

 

Several studies shows that scorpions are selective when it comes to sting and venom use i defense and prey capture. The basis for this is that venom is costly to replace and this cause the scorpions to be restrictive in using venom.

Lindsay Marston and co-workers recently published a study where they tested antipredator behaviors of Centruroides sculpturatus Ewing, 1928 (Buthidae) exposed to two different "threats" in their natural environment. 

Interestingly, the results of the different experiments contrasted with those of previous studies.The article discuss possible reasons for this.

Abstract:
Scorpion antipredator behavior incorporates risk assessment that informs decision-making and venom usage. We quantified antipredator behaviors of the clinically significant Arizona bark scorpion (Centruroides sculpturatus) in their natural environment using exposure to two stimuli: a freshly thawed laboratory mouse (Mus musculus) and a membrane-covered glass beaker. We videotaped and compared envenomation behaviors between sexes (females, gravid females, and males), across sizes, and between animal orientations (on vertical or horizontal substrates). Results failed to show consistent support for any of our four hypotheses. Females (especially gravid females) were no more likely than males to exhibit higher levels of stinging and venom expenditure. Scorpions on horizontal surfaces compared to those on vertical surfaces, and larger scorpions compared to smaller ones, were likewise no more likely to exhibit higher levels of responsiveness. Mice were more likely to be stung than the membrane-covered beaker, but with fewer and briefer stings, suggesting the scorpions did not attempt to deliver more venom into the mice. Thus, we discerned no clear patterns in risk assessment, stinging, and venom use associated with sex, substrate orientation, body size, or threat stimuli. These findings contrasted with those of several prior laboratory studies. Variation from unaccounted environmental variables may have obfuscated divergent behavioral tactics. Nevertheless, the behaviors we document here provide insights on the range of defensive behaviors exhibited by C. sculpturatus under natural environmental conditions, including the frequency of dry stings (11.8%) to the membrane-covered beakers.

Reference:
Marston LA, Fox GA, Hung KY, Delo SJ, Hayes WK. A Sting Operation: Risk Assessment and Venom Expenditure by Arizona Bark Scorpions (Centruroides sculpturatus) in a Defensive Context. Toxins. 2025;17(4):198. [Open Access]

Bad scorpion kills beautiful tarantula

 

Lizbeth Parra Mendoza and co-workers have not published a crime story, but an observation of a Centruroides elegans (Thorell, 1876) (Buthidae) preying on a juvenile tarantula of the species Bonnetina cyaneifemur Vol, 2000 in an area in Jalisco, Mexico.

There are few records of scorpions preying on tarantulas, but not surprising because of the scorpions being generalist predators. 

Abstract:
Tarantulas and scorpions have an important intraguild predation relationship, with spiders acting as predators in most cases. However, scorpions can prey on tarantulas, especially juveniles. We present a case of scorpion predation on the tarantula Bonnetina cyaneifemur in a Mexican dry forest. A juvenile B. cyaneifemur was found in the vegetation with its prosoma partially eaten by a female scorpion Centruroides elegans. Our record increases the number of known predators for the Mexican tarantula B. cyaneifemur and provides information on a trophic niche of the species.

Reference:
Mendoza LP, Lira AFdA, Gonzalez-Santillan E. Record of a tarantula Bonnetina cyaneifemur preyed upon by Centruroides elegans. Southwestern Entomologist. 2025;50(2):1–6. [Subscription required for full text]

Thanks to Andre for sending me this article!

The postembryonic development of Centruroides ochraceus from Mexico

 

Happy New Year!

Wilson Lourenco and Eric Ythier have recently published some old observations of postembryonic development of Centruroides ochraceus (Pocock, 1898) (Buthidae) from Yucatan, Mexico. It is also suggested that parthenogenesis exists in this species.

Abstract:
Since general data on the biology of scorpions remain rare, we propose in this note some results on the postembryonic development of the buthid scorpion Centruroides ochraceus (Pocock, 1898), species distributed in the Yucatan peninsula, Mexico. The results were originally observed almost 40 years ago, based on some specimens collected by the senior author. A possible case of parthenogenesis is also suggested for this species.

Reference:
Lourenço WR, Ythier E. The postembryonic development of Centruroides ochraceus (Pocock, 1898) from Yucatan, Mexico (Scorpiones: Buthidae), with comments on parthenogenesis. Revista Iberica de Arachnologia. 2024(45):119-22. [Full text supplied by author]

Rediscovery of the rare species Paruroctonus williamsi from Big Bend National Park, Texas USA

 

Matthew Leister recently published an article informing about the rediscovery of the rare scorpion Paruroctonus williamsi Sissom & Francke, 1981 (Vaejovidae). Several researchers have tried to find this species again in the last 50 years, but it has stayed hidden until now. Several specimens were discovered in The Big Bend National Park in Texas, USA.

Abstract:
A recent search at Big Bend National Park has recovered specimens of Paruroctonus williamsi after a lapse of over 50 years with no records of the species, underscoring the importance of continued monitoring for rare species. This study includes photographs of living specimens, documentation of their habitat, comparisons with other species of Paruroctonus found at Big Bend National Park, and a list of scorpions observed near P. williamsi.

Reference:
Leister M. Rediscovery of a rare species of Paruroctonus (Scorpiones: Vaejovidae) from Big Bend National Park, Texas. Western North American Naturalist. 2024;84(4):524–7. [Subscription required for full text]

Thanks to Luis A. Roque for sending me this article!

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!

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!

A new species of Vaejovis from Mexico

 

Gerardo A. Contreras Félix and José L. Navarrete Heredia have recently published a description of a new spcies of Vaejovis C.L. Koch, 1836 (Vaejovidae) from Michoacan in Mexico.

Vaejovis castanoae Contreras-Felix & Navarrete Heredia, 2024

Abstract:
A new species of Vaejovis is described for Michoacan, Mexico belonging to the nigrescens/nitidulus group, the less diverse group of species from the genus. This species has a preference for synanthropic environments and inhabits rock walls within the city limits. Additionally, the pictures of the hemispermatophore are presented and characters are named according to new terminology. This species is named honoring Dr. Gabriela Castaño Meneses for her great contributions to arthropods research in Mexico and the world.

Reference:
Félix GAC, Heredia JLN. Hidden in the cracks, a new species of Scorpion from Michoacan, Mexico (Scorpiones: Vaejovidae). Dugesiana. 2024;31(2):159-73. [Open Access]

Thanks to Gerard Dupre for sending me this article!

Family Vaejovidae

The scorpion fauna of Aguascalientes, Mexcio

 

Mexico has one of the highest diversity of scorpions in the world. Fernanda Chávez-Samayoa and co-workers have recently published an article on the richness and composition of the scorpion fauna
of Aguascalientes, Mexico.

The article has an identification key for the taxa in this area.

Abstract:
The scorpion fauna of the state of Aguascalientes was revised based on specimens deposited in scientific collections and fieldwork. We evaluated the completeness of the scorpion species inventory of the Colección Zoológica of the Universidad Autónoma de Aguascalientes (CZUAA) based on nonparametric estimators. The results indicate that the number of species increased from 11 to 13, recording for the first time Chihuahuanus glabrimanus (Sissom & Hendrixson, 2005), a psammophilic species, and Centruroides balsasensis Ponce-Saavedra and Francke, 2004, a medically relevant species for public health. Finally, an identification key to the scorpion species of Aguascalientes is provided and a recount of ecological and biological traits of the species herein is studied.

Reference:
Chávez-Samayoa F, Antonio Escoto-Moreno J, González-Santillán E. Richness analysis and completeness of the scorpion fauna of Aguascalientes, Mexico with an identification key to species. Revista Mexicana de Biodiversidad. 2024;95:e955380. [Open Access]

Thanks to Fernanda Chávez-Samayoa for sending me their article!

More on the function of the pectines in scorpion navigation

 

There have been a lot of research on the morphology and the functions of the pectines, which is a unique organ found only in scorpions (Solifigae has a similar organ called malleoli or racquet (or racket) organs). Most of the research so far have focused on the "taste function" (the detection of chemical cues), but it also seems that the pectines have a "feeling function" (having mechanosensory abilities). Overall, the pectines help scorpions find food, navigate, avoid predators and find mates.

Hannah Peeples and Douglas Gaffin recently published a study investigating the role of the peg sensilla on scorpion pectines for mechanosensory responses. This is a very technical paper, but as far as I can tell the main conclusion is that pectines use mechanosensory stimuli to navigate in its activity area, to find home to its shelter and to retrieve dropped insect prey.

Abstract:
Scorpions possess midventral touch/taste organs called pectines, which may be important for learning the nuances of the substrate during navigation as well as the detection of pheromones, spermatophores, and food. The pectines possess thousands of minute structures called peg sensilla that are responsive to both chemicals and mechanical deflection of the peg shaft. While much is known about the chemical responsiveness of the pegs, very little is known about their mechanosensory properties. Here we ask if the peg mechanosensory response is “all-or-nothing” or graded depending on the intensity of stimulation. We made electrophysiological recordings of neural activity from individual peg sensilla while deflecting the peg to elicit apparent mechanosensory responses. Our records show the presence of a rapid firing (.100 Hz), quickly adapting waveform that is indicative of a mechanoreceptor and appears to be independent of previously identified chemo-responsive cells. We tested mechanosensory response dynamics in two ways. The first test focused on a shorter-duration touch versus a longer-duration touch, while the second focused on a smaller deflection versus a larger deflection. Both pairs of stimulations (short vs long touch; small vs large touch) produced repeatable and statistically distinct responses in terms of spiking frequency. These results indicate the mechanosensory responses of peg sensilla are graded, which sheds light on the textural resolvability of the pectines and informs models of the type of information that scorpions obtain while assessing surfaces in their environment.

Reference:
Peeples HM, Gaffin DD. An assessment of the mechanosensory responses of peg sensilla on scorpion pectines. The Journal of Arachnology. 2024;52(1):1-8.

Thanks to Matt Simon for informing me about this article and for providing insight about the article!

Mexican Scorpions Described between 2000 - 2023

 

Gerardo Contreras-Félix and José Navarrete-Heredia have recently published an article where they sum up all Mexican Scorpions Described between 2000 - 2023. In addition to listing up the species and their associated genera and family, the article also presents an overview of the journals that these articles appear in.

Abstract:
Patterns of descriptions of new species of Mexican scorpions between 2000-2023 were analyzed. We based our study on the Zoological Record of Web of ScienceTM. We found 111 species in seven families described in 83 papers published in scientific journals from all over the world. Families with the most species described were Vaejovidae (52), Buthidae (26), Diplocentridae (23), Euscorpiidae (4), and Typhlochactas (3). The species of Mexican scorpions were described in Revista Mexicana de Biodiversidad, Zootaxa, Revista Ibérica de Aracnología, and 19 other publications. We also comment on issues to consider when Zoological Record was used for analysis in this study.

Reference:
Contreras-Félix GA, Navarrete-Heredia JL. Mexican Scorpions Described between 2000 - 2023: Analysis from Zoological Records of Patterns, Trends, and Effects of Lockdown Over Descriptions. Southwestern Entomologist. 2024;49(1):100-19. [Subscription required for full text]

In Memoriam Richard F. Ayrey (1948 – 2024)

Previously this year we got the sad news that scorpion researcher and enthusiast Richard Ayrey had passed. The Euscorpius journal recently published a memorial article honoring Rich's life and work on scorpions.

 RIP.

Abstract:
This is a memorial issue honoring Richard F. Ayrey (1948 – 2024), a US scorpiologist. A full list of his 26 works is appended, as well as a list of scorpion taxa described by Richard (two genera and 19 species of Vaejovidae), and a map of their type localities in the USA and Mexico.

Reference:
DeBoer-Ayrey M, Myers BT, Bryson Jr RW, Webber MM, Graham MR, Lowe G, et al. In Memoriam Richard F. Ayrey (1948 – 2024). Euscorpius. 2024(384):1-11. [Open Access]