A review on endemic scorpion species and subspecies in Morocco

 

Scorpions are a health problems in some regions of the world, among them Morocco. Knowledge about the scorpion fauna and the distribution of medical important species is important so that local and regional health providers can be prepared for sting accidents and envenomations. Information like this is also important for measures to prevent sting incidents.

Meriem Es-Saadi and co-workers recently published a review on endemic scorpion species and subspecies in Morocco. Their study identified fifty-five endemic species and subspecies in Morocco. Not surprisingly, the family Buthidae was most widespread. Knowledge about the distribution of the species in this family is important, as the most medical important species are members to this family.

Abstract:
Scorpion fauna is abundant in regions with arid and semi-arid climates, exposing these areas to a risk of envenomation, especially for children. Scorpion envenomations cause thousands of deaths each year, with notable incidences in the MENA region, South America, Latin and Central America, and India. Morocco is one of the countries most affected by this phenomenon; according to statistics from the Moroccan Poison Control and Pharmacovigilance Center (CAPM), approximately 8565 scorpion stings and envenomations were recorded annually between 2016 and 2022, mainly among children. A literature review was conducted to identify and catalog the endemic scorpion species in Morocco and explore the impact of climate change on their distribution. Sources included scientific journal articles, university theses, and field reports. The collected data were compiled and analyzed to create a distribution map of the endemic species. Our results identified fifty-five endemic species and subspecies in Morocco. The family Buthidae is the most widespread, with seventeen endemic species of the genus Buthus, nine of the genus Androctonus, five of the genus Butheoloides, four of the genus Buthacus, two each of the genera Orthochirus, Compsobuthus, and Hottentota, and one species each of the genera Microbuthus, Cicileiurus, and Saharobuthus. The family Scorpionidae includes nine endemic species, and two subspecies belonging to the genus Scorpio. A high level of endemism is observed in southern Morocco, highlighting a significant concentration of these species in this region. Ongoing climate change is likely to expand the population and distribution of scorpions, as well as the number of envenomations. The results underscore the importance of implementing control and prevention strategies to reduce the risks of envenomation, particularly in the context of climate change. Therefore, to develop management and prevention strategies is based on a thorough understanding

Reference:Es-Saadi M, Hamdi S, Khourcha S, Sadki K, Errafii K, Oukkache N. Endemic Scorpion Species and Subspecies in Morocco: A Comprehensive Overview. Toxicon. 2025;255:108253. [Subscritpion required for full text]

A new species of Isometrus (Reddyanus) from caves in Myanmar

 

Update 29.01.25:  In agreement with author Eric Ythier, the new species has been included in the genus Reddyanus in The Scorpion Files to avoid any confusion until the status of  Reddyanus has ben resolved. 

 Reddyanus alessandroi (Lourenco & Ythier, 2025)

Eric Ythier and Wilson Lourenco have recently published a new species of Isometrus Ehrenberg, 1828 (Buthidae) from Saddan Cave in eastern Myanmar (Burma).

 Isometrus (Reddyanus) alessandroi Lourenco & Ythier, 2025

The authors do not accept the genus status for the subgenus Reddyanus Vachon, 1972, which is used in The Scorpion Files. I have listed the new species in Isometrus, but it probably belongs in Reddyanus (depending on how you view the status of the genus/subgenus).

The new species was found in a cave, but has no troglomorphic characters.

Abstract:
A new species belonging to the genus Isometrus Ehrenberg 1828, subgenus Reddyanus Vachon, 1972, is described from Myanmar: Isometrus (Reddyanus) alessandroi sp. n., which was collected in Saddan Cave, located in Kayin State, in the East of the country. In recent years the number of new species added to both subgenera Isometrus and Reddyanus have increased remarkably. Nevertheless, none of these descriptions concerned Myanmar. This particular geographic situation as well as a combination of several morphological features led us to propose here this new species.

Reference:
Ythier E, Lourenco WR. A new cave species of Isometrus Ehrenberg 1828 from Myanmar (Scorpiones: Buthidae). Faunitaxys. 2025;13(4):1-6. [Open Access]

Thanks to Eric for sending me their new article!

Family Buthidae

A study of Androctonus in Iran revels new species

 

Hossein Barahoei and co-workers recently published a study of Androctonus Ehrenberg, 1828 found in Iran. They report of a new species from Eastern Iran.

Androctonus rostami Barahoei, Mirshamsi, Amiri, Moeinadin & Rakhshani, 2025

The number of species in the genus from Iran is now five: A. crassicauda (Olivier, 1807), A. kunti Yagmur, 2023,  A. sistanus Barahoei & Mirshamsi, 2022, A. sumericus Al-Khazali & Yagmur, 2023 and A. rostami Barahoei, Mirshamsi, Amiri, Moeinadin & Rakhshani, 2025.

The distribution range of the studied species in Iran is outlined and mapped. 

Abstract:
Two species of Androctonus have been reported to date from Iran: Androctonus crassicauda (Olivier, 1807) and A. sistanus Barahoei and Mirshamsi, 2022, which is distributed only in the southeast of Iran. Investigating and identifying the distribution range of dangerous species is critically important for scorpion management. A total of 105 specimens of Androctonus were collected from representative locations in Esfahan, Yazd, Kerman, Hormozgan, Hamadan, and Khuzestan provinces. These samples were studied morphologically, morphometrically, molecularly (COI gene sequencing), and through species distribution modeling (SDM) using the MaxEnt model. Four Androctonus species were identified through the morphological and molecular studies: A. crassicauda, A. sistanus, A. sumericus, and A. rostami sp. nov. (from eastern Iran). The four described species of Androctonus in Iran form well-defined phenetic groups based on morphometric analyses. SDM results indicated that all predicted models have high accuracy and some overlap with each other. Temperature seasonality for A. crassicauda and annual precipitation for A. sistanus, A. rostami, and A. sumericus were the highest contributing variables. With this first Iranian report of A. sumericus, the description of a new species, and the presence of A. kunti in the northwest of Iran, the number of species of this genus in the country is increased to five. The distribution range of the studied species in Iran is outlined and mapped. The potential distribution modeling for the current period delineated the distribution range of each of the four sampled species. Considering the lethality of the venom of Androctonus scorpions, determination of species distribution ranges provides theoretical backing for studies of significant importance for the prevention of scorpion stings, as well as a foundation for further biochemical and serological studies to develop specific antivenoms for each species.

Reference:
Barahoei H, Mirshamsi O, Amiri M, Moeinadini A, Rakhshani E. Integrative taxonomy reveals the existence of a new species of fat-tailed scorpion Androctonus (Buthidae) in Iran. Turkish Journal of Zoology. 2025;49. [Full text not available yet]

Thanks to Gerard for sending me this article!

Family Buthidae

A study of prey capture and foraging in the buthid Buthus montanus from Spain

 

Francisco Sanchez-Pinero and co-workers recently published a study of foraging strategies and prey selection in Buthus montanus Lourenco & Vachon, 2004 (Buthidae) from an arid area in southeastern Spain.

The study shows that Buthus occitanus is a generalist predator that capture a wide range of prey types. Cannibalism is a major part of the diet. This species has a varied hunting ground as it was observed to hunt for prey on the ground surface, below ground and in shrub canopies.

Abstract:
Scorpions are diverse and abundant in tropical and subtropical regions worldwide, especially in arid ecosystems where they play a relevant role as predators. However, few studies have examined diet composition, use of alternative foraging strategies, prey selection, and predator-prey size relationships of scorpions in different microhabitats. This study provides an analysis of the diet of Buthus montanus Lourenco & Vachon, 2004 in an arid area of SE Spain. Prey captured by scorpions were recorded during black-light censuses over the main activity season of B. montanus in the study area. Because scorpions were observed capturing prey on the ground surface, below ground, and in vegetation, prey availability was estimated using complementary methods for shrub- and ground-dwelling prey. Results show that B. montanus is a generalist predator that feeds on a diverse array of prey, although predatory arthropods and tenebrionid larvae comprised the highest proportion of its diet in both number of prey and biomass. Cannibalism was a major component of its diet, accounting for almost 25% of the biomass ingested, especially in large scorpions. The composition of the diet, prey-size variability, and predator-prey size relationship showed size-related differences. These size-related variations in the diet were also linked to habitat use, due to climbing vegetation by smaller scorpions. These results highlight the implications of ontogenetic shifts in the diet of B. montanus related to cannibalism by larger scorpions and climbing vegetation by smaller individuals, causing changes in the type of prey used by individuals of different size and predator-prey size relationships.

Reference:
Sánchez-Piñero F, Urbano-Tenorio F, Puerta-Rodríguez L. Foraging strategies, prey selection and size- and microhabitat-related diet variation in Buthus montanus (Scorpiones: Buthidae) in an arid area of SE Spain. The Journal of Arachnology. 2025;52(3):189-98. [Subscription required for full text]

Updated information about the distribution of the genus Scorpio in Northern Algeria and a redescription of Scorpio trarasensis

 

Eric Ythier and co-workers recently published an article with updated information about the Scorpio Linnaeus, 1758 (Scorpionidae) fauna in Northern Algeria. The authors also present a redescription of Scorpio trarasensis Bouisset & Larrouy (1962). The article also includes an identification guide for the Scorpio species known from Northern Algeria.

Abstract:
Scorpio trarasensis Bouisset & Larrouy (1962), from the Trara Massif, in the western part of the Tellian Atlas of Algeria, is redescribed on the basis of new material collected and a neotype is designated (original type material is considered lost). The geographical distribution of the genus Scorpio Linnaeus, 1758 in Northern Algeria is updated based on additional material examined, and a key for their identification is proposed.

Reference:
Ythier E, Hammou MA, El Bouhissi  M, Mairif M. Redescription of Scorpio trarasensis Bouisset & Larrouy, 1962 and update on the distribution of the genus Scorpio linnaeus, 1758 in Northern Algeria (Scorpiones: Scorpionidae). Arachnides. 2025(120):1-11. [Open Access]

Thanks to Eric and Gerard for sharing this article with me!

Family Scorpionidae

Extinct family Chaerilobuthidae from Mid-Cretaceous Burmese amber with 16 species are now a part of the extant family Pseudochactidae

 

In a recent article, Qiang Xuan and co-workers have analyzed the taxa in the extinct family Chaerilobuthidae Lourenço and Beigel, 2011. This family originally consisted of 3 genera and 16 species. All taxa are based on fossil specimens found in Mid-Cretaceous Burmese amber.

The authors conclude that the family Chaerilobuthidae should change status to subfamily (Chaerilobuthinae) and placed in the extant family Pseudochactidae Gromov, 1998. The two extinct genera Chaeriloiurus Lourenço, 2020 and Serratochaerilobuthus Lourenço, 2024, are synonymized with Chaerilobuthus Lourenço and Beigel, 2011 which contains 16 species (all extinct).

Chaerilobuthinae with its taxa is now listed in The Scorpion Files for Pseudochactidae, but are not included in the count of number of taxa which only includes extant taxa.

Abstract:
The extinct scorpion family Chaerilobuthidae Lourenço and Beigel, 2011, endemic to Burmese amber, was initially established due to its unique pedipalp trichobothrial pattern related to the Type A and Type B patterns of families Buthidae C.L. Koch, 1837 and Chaerilidae Pocock, 1893, respectively. The present contribution describes 11 new specimens, representing seven species of Chaerilobuthidae from Mid-Cretaceous Burmese amber, revealing their morphology using various imaging technologies. A revised diagnosis of Chaerilobuthus Lourenço and Beigel, 2011 is provided based on new morphological characters of the carapace, ocelli, chelicera, pedipalp trichobothria, coxapophyses, and leg tarsi. The other two genera of Chaerilobuthidae, Chaeriloiurus Lourenço, 2020 and Serratochaerilobuthus Lourenço, 2024, are synonymized with Chaerilobuthus based on a reassessment of their morphological characters and morphometric analysis, creating Chaerilobuthus brigittemuellerae (Lourenço and Velten, 2020), comb. nov. and Chaerilobuthus schmidti (Lourenço and Velten, 2024), comb. nov.. The systematic position of Chaerilobuthidae is clarified based on phylogenetic analyses of an updated morphological character matrix for Pseudochactidae Gromov, 1998, an extant family in Asia. Phylogenetic analysis placed Chaerilobuthidae sister to the pseudochactid subfamily Vietbocapinae Lourenço, 2012, justifying its transfer to Pseudochactidae, as Chaerilobuthinae Lourenço and Beigel, 2011, stat. nov.. This discovery confirms that Pseudochactidae date back 100 Mya and contributes to understanding the origin and evolutionary history of this relictual family.

Reference:
Xuan Q, Prendini L, Engel MS, Cai C, Huang D. Extinct scorpion family Chaerilobuthidae from Mid-Cretaceous Burmese amber reinterpreted as subfamily of extant family Pseudochactidae (Chelicerata: Scorpiones). Zoological Journal of the Linnean Society. 2025;203(1):zlae169. [Subscription required for full text]

Thanks to Gerard for informing me about this article!

Family Pseudochachtidae

Does the cuticular wax layer in scorpions have a role in mate and sexual recognition in male Tityus pusillus?

 

Male and female scorpions need to be able to recognize each others and their "mood" to ensure safe and optimal mating. The mating dance in scorpions is well known and many studies have indicated that chemical substances are involved in mate and sexual recognition.

Hugo R. Barbosa-da-Silva and co-workers have recently published a study investigating the cuticular wax layer (CWL) involvement in mate and sexual recognition in the buthid Tityus pusillus Lourenço, 2013. The study found some evidence that CWL compounds were involved in sexual recognition, but there was noconfirmation that CWL compounds mediate mate recognition in this species. 

Abstract:
Hydrophobic compounds present in the cuticular wax layer (CWL) of terrestrial arthropods protect them from dehydration and are also involved in chemical communication. However, the role of CWL compounds in the behavioral ecology of scorpions has been studied less often, with most investigations focusing on their responses to mechanical stimuli. In this study, we aimed to characterize the CWL composition of Tityus pusillus (Scorpiones, Buthidae) and examine the influence of CWL solvent extracts and movement on intraspecific mate and sexual recognition by males of this species. We analyzed CWL hexane extracts of adult female and male T. pusillus by gas chromatography-mass spectrometry (GC-MS). In paired behavioral tests inside an experimental arena, we exposed adult males to i) live and intact dead conspecific females; ii) intact dead females and females without the CWL (removed with solvent washes); and iii) intact dead males with and without the CWL. Our results showed that CWL extracts of both female and male T. pusillus contained a series of linear alkanes (C21 – C34; > 54 % relative composition), as well as fatty acyls (> 9.5 %) and methyl-branched alkanes (> 9.1 %). Two unassigned C31 monomethyl-branched alkanes were exclusively identified in male CWL extracts (~ 4.7 %), while female samples contained high relative concentrations (> 22.5 %) of sterol derivatives, present only as minor constituents in male samples. Male T. pusillus performed sexually-oriented behavioral acts when paired with both live and dead conspecific females, intact or without the CWL. However, they ignored conspecific dead males. Our results show that CWL compounds have a role in intraspecific sexual recognition by male T. pusillus but only the CWL compounds does not explain mate recognition.

Reference:
Barbosa-da-Silva HR, Pontes WJT, Lira AFA, Navarro DMAF, Salomão RP, Maia ACD. The role of intraspecific mechanical and chemical signaling for mate and sexual recognition in male Tityus pusillus (Scorpiones, Buthidae). Zoology. 2025;168:126235. [Subscription required for full text]

Thanks to André for sending me their article!

Goats are not scorpions' best friend

 

                                                    Illustration: DALL-E/ChatGPT

Habitat destruction due to human impact is a threat to many animals, scorpions included. In a recent study, Thayna Rhayane Brito-Almeida and co-workers have investigated the impact of non-native, grassing goats on the scorpion fauna in Brazil.

The study showed that the goats have a negative impact on the habitat and both the species richness and abundance of scorpions in areas with grazing goats. The presence of goats also seemed to cause reduced body mass and size in the scorpions compared to areas without goats.

Abstract:
Extensive grazing carried out freely by exotic goats represents an important source of anthropogenic degradation in seasonally dry tropical forests of Brazil. The presence of these herbivores may negatively impact the local fauna through the reduction of habitat complexity. In this study, we investigate the effect of goat farming in scorpion assemblage from Brazilian seasonally dry tropical forest. Scorpions were sampled in 36 areas (18 disturbed and 18 undisturbed) distributed in three sites in the seasonally dry tropical forest of Brazil. At each location, we recorded a set of local variables such as litter depth, diameter at breast height of trees, vegetation density (trees and shrubs), and detritus (stones and fallen logs). In total, 396 scorpions were collected, distributed across six species and two families. Our results showed that scorpion diversity was negatively affected, with species richness and abundance reduced in areas influenced by goats. Furthermore, in these sites, the composition of the species was also affected, with habitat-generalist species favoring habitat-specialist species. Finally, sites with free pasture of goats presented scorpions with reduced body condition (body mass and size) than sites without goats. Furthermore, habitat degradation caused by free pasture of goats negatively affects the assemblage of scorpions in terms of their diversity and body condition the seasonally dry tropical forest of Brazil.

Reference:
Brito‐Almeida TR, Foerster SÍA, Lima JR, da Silva MA, de Moura GJB, de Araujo Lira AF. Free Pasture of Exotic Goats Reduces Diversity and Negatively Affects Body Condition in Scorpions (Arachnida: Scorpiones) Assemblage From Brazilian Seasonal Dry Tropical Forest. Ecology and evolution. 2025;15(1):e70804. [Open Access]

Thanks to André for sending me their article!

A review of the scorpion fauna of China

 

There is still a lot to learn about the large scorpion fauna of China, both when it comes to new taxa but also by evaluating old works. Victoria Tang has recently published a new review of the scorpion fauna of China. 

The article focuses especially on the genera Reddyanus Vachon, 1972 and Razianus Farzanpay, 1987 (both Buthidae). The following taxonomical changes were made:

Raised to species status from synonymization:

Reddyanus hainanensis (Lourenço, 2005) Restored from synonymy with Isometrus petrzelkai Kovarík, 2003.

Reddyanus lao (Lourenço & Leguin, 2005) Restored from synonymy with Isometrus petrzelkai Kovarík, 2003.

 Synonymization:

 Reddyanus tibetanus (Lourenco & Zhu, 2008) is synonymized with Reddyanus assamensis (Oates, 1888).

New status:

Reddyanus kanak Lourenço, 2023 is tentatively considered as a nomen dubium.

An updated catalogue of scorpiofauna of China is also provided.

Abstract:
Two genera associated with the scorpiofauna of China are reviewed, Razianus Farzanpay, 1987 and Reddyanus Vachon, 1972. Holotype female of Razianus xinjianganus Lourenço et al., 2010 is presumed to be lost, as well as all type material of other Chinese scorpions described before 2020. Comments are given on the species composition of genus Reddyanus with a new synonym: Isometrus (Reddyanus) tibetanus Lourenço & Zhu, 2008 = Reddyanus assamensis (Oates, 1888) syn. n. Reddyanus kanak Lourenço, 2023 is tentatively considered as a nomen dubium. An updated catalogue of scorpiofauna of China is provided, including their type locality and type depository, protonym, synonym(s), misidentification(s), Chinese equivalent name and distribution in China. Several Tibetan Scorpiops species will be addressed in a subsequent paper. Finally, a list of errata in the preceding taxonomic papers by the current author is also included.

Reference:
Tang V. A review of scorpiofauna of China: nomenclatural notes and updated faunistic catalogue (Arachnida: Scorpiones). Euscorpius. 2025(404):1-24. [Open Access]

Family Buthidae

Did you miss anything in 2024?

 

In the recent issue of Arachnides, Gerard Dupre presents two articles that sum up the scorpion year of 2024. One article list all scorpion papers published last year, the other article list all new taxa.

References:
Dupre G. Scorpions bibliography 2024 (without toxinology). Arachnides. 2024(119):1-20. [Open access]

Dupre G. Nouveaux taxa de scorpions pour 2024. Arachnides. 2024(119):21-7. [Open Access]

Thanks to Gerard for sharing the articles of Arachnides with us!

Arm-span competition between males in the buthid scorpion Tityus rosenbergi

 

Courtship and mating behaviors between male and female scorpions are well documented. Intrasexual interactions (between female-female or male-male scorpions) are not mentioned often in the literature. Recently, a new ritualized behavior between the same sex was described and labeled "arm-span competition”.

In a recent article, Jules Thornton Wyman and co-workers present observations of "arm-span competition" between males of Tityus rosenbergi Pocock, 1898 (Buthidae). The behavior is interpreted as a ritualized male-male contests. 

The authors suggest that the elongated pedipalps seen in males of many species might be the result of selective pressure related to ritualized arm-span competition.

Abstract:
Although courtship and mating behaviors have been described for nearly all scorpion lineages, intrasexual interactions in scorpions remain understudied. Recently, a novel ritualized behavioral unit, termed “arm-span competition,” in which individuals face off and extend their pedipalps laterally, was described from analyses of male-male contests in several scorpionid species. Here, we present the first documented observation of arm-span competition in a buthid scorpion, Tityus cf. rosenbergi Pocock, 1898. Interestingly, both T. cf. rosenbergi and most scorpionid species known to engage in arm-span competition exhibit a similar sexual dimorphism: males have markedly longer and more slender pedipalps than females. We suggest that the elongated pedipalps in males of these species might be the result of selective pressure related to ritualized armspan competition. We also highlight the potential for citizen science to contribute rare observations to scientific literature.

Reference:
Wyman JT, Wright-Ueda J, Agnew Q, Castellano I, Simone Y. First report of arm-span competition in buthid scorpions: male-male contest in Tityus cf. rosenbergi Pocock, 1898. The Journal of Arachnology. 2025;52(3):210-3. [Open Access]

Thanks to Yuri for sending me this article!

A study of the fluorescent sensilla on the scorpion aculeus (stinger)

 

It is well-known that scorpions fluorescence under UV light. This also apply for the scorpion's stinger (aculeus), but previous studies has shown a lack of fluorescence in the distal aculeus. Graeme Lowe has recently published an article where he used SEM imaging to study UV fluorescence in the acuelus of many species.

He observed numerous brightly fluorescent punctae in the non-fluorescent distal aculeus. These punctae were identified as aculear sensilla coeloconica (ASC). The ASC probably have a chemoreceptive function.

The author suggests that the ASC are playing an important role in the sensory coordination of telson function when the scorpions are trying to sting their prey and inject venom.

Abstract:
The aculeus of the scorpion telson was studied by UV fluorescence microscopy. Numerous brightly fluorescent punctae were observed on the non-fluorescent distal aculeus, including the tip region. The punctae were identified as aculear sensilla coeloconica (ASC), and were connected to fluorescent canals running through the cuticle. ASC were present in both sexes, and in adults and immatures as early as the second instar juvenile, but were absent from the first instar. The distal aculeus was found to be encased in a thick, non-fluorescent dark exocuticle (DX), covering an underlying thin, fluorescent hyaline exocuticle (HX). Fluorescent ASC were recorded from 183 species belonging to 97 genera in 19 families, encompassing all major scorpion lineages. The number of ASC in the tip region, the width of ASC canals, and the depth of the tip region, all exhibited positive correlation and allometric scaling with respect to carapace length. Higher tip densities of ASC occurred in some buthids, and in Scorpionoidea. The ASC are probably ubiquitous across the Order Scorpiones, playing an essential role in the sensory coordination of telson function during prey envenomation.

Reference:
Lowe G. Star-studded stingers: fluorescent sensilla on the scorpion aculeus (Arachnida: Scorpiones). Euscorpius. 2024;2024(402):1-39. [Open Access]

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]