The Scorpion Files Newsblog

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]

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]

More Christmas species. Hossein Barahoei and Mehran Shahi just published a description of a new species of Odontobuthus Vachon, 1950 (Buthidae) from Southern Iran.

Odontobuthus persicus Barahoei & Shahi, 2024

The article has an updated identification key for the genus.

Abstract:
Odontobuthus Vachon, 1950, with nine described species, is a genus of digger scorpions in the Buthidae family, which can be distinguished by having large tooth-like processes on the ventrosubmedian carinae of the second and third metasomal segments. Morphological and molecular investigation of coastal specimens from the Hormozgan province in Iran led to the discovery of a new species named Odontobuthus persicus sp. nov. that is described here. It is closely related to O. chabaharensis morphologically. The new Odontobuthus species has two large and conical tooth-like processes on ventrosubmedian carinae of the second and third metasomal segments, while O. chabaharensis has three or four medium to large tooth-like processes. Based on phylogenetic analysis using partial COI sequences, the new species is placed as a sister taxon of O. brevidigitus. Genetic differences with the other species of Odontobuthus (mean = 0.107) confirmed the validity of this species.

Reference:
Barahoei H, Shahi M. New Species of the Digger Scorpions, Odontobuthus Vachon, 1950 (Buthidae) from Southern Iran. Zoological Studies. 2024;63(48). [Open Access]

Thanks to Kian for sharing this article with me!

Family Buthidae

No Christmas holiday for scorpion news! Happy Seasons Greetings everyone! 

Ersen Yagmur and co-workers recently published an article describing two new species of Scorpio Linnaeus, 1758 (Scorpionidae) from Southeastern Turkey.

Scorpio karakurti Yagmur, 2024

Scorpio Sirnakensis Yagmur, 2024

Abstract:
Two new species, Scorpio karakurti sp.n. and S. sirnakensis sp.n. are described and illustrated from the Southеastеrn region of Turkey. S. karakurti sp.n. is detected from Batman and Diyarbakır provinces and can be distinguished from all species of the genus Scorpio by its higher pectinal teeth numbers, especially in males (10–11 in females and 11–15 in males). S. sirnakensis sp.n is detected from Şırnak province and can be distinguished by elongated chela and telson shape and genital operculum shape of females. The new species are compared with the known species of the genus Scorpio Linnaeus, 1758 in the Middle East.

Reference:
Yagmur EA, Hussen FS, Karakurt S, Kurt R, Sipahioglu Ö, Kartal I. Two new species of the genus Scorpio L., 1758 from Southеastеrn Turkey (Scorpiones: Scorpionidae). Arthropoda Selecta. 2024;33(4):559-89. [Open Access]

Thanks to Ersen for sending me their new article!

Family Scorpionidae

Tonight, Victoria Tang published a description of a new species of Scorpiops Peters, 1861 (Scorpiopidae) from Yunnan, China.

Scorpiops reini Tang, 2024

In my opinion, a very beautiful and interesting scorpions, but then again I'm probably not objective when I'm writing this ;) 

Abstract:
Scorpiops reini sp. n. is described from Yingjiang County (Dehong Prefecture, Yunnan Province) based on an adult pair. It can be readily discriminated from all of its congeneric geographic neighbors in Yunnan, namely S. jendeki Kovařík, 1994, S. shidian (Zhu et al., 2005), S. tongtongi Tang, 2022, and S. zhangshuyuani (Ythier, 2019). Within Yunnan, it resembles S. validus (Di et al., 2010) and S. yangi (Zhu et al., 2007) most, but can be identified by its large median ocelli (relative to the width of ocular subislet), pedipalp chelal finger morphology and pectinal tooth count. Beyond Yunnan, it shows the highest similarity with S. beccaloniae (Kovařík, 2005), from which it distinguishes itself mainly by a different chelal morphology (weaker finger lobe and notch, longer and narrower manus with chelal carinae composed of smaller and denser granules). The validity of this new species is supported molecularly (to be published). The ocular islets are reviewed for all Yunnan Scorpiops.

Reference:
Tang V. Scorpiops reini sp. n. from Yunnan, China (Scorpiones: Scorpiopidae). Euscorpius. 2024(403):1-19.

A big thanks to Victoria for naming this species after me!

Family Scorpiopidae

Scorpions prey on a large variety of other invertebrates and even on some small vertebrates. Camel spiders (Solifugae) is another fierce arachnid predator inhabiting the same habitats as many scorpions. These two arachnids probably prey on each other when they have the opportunity. 

Noureddine Benali and co-workers recently published a case of natural predation on a solifugid by Buthus apiatus Lourenço, El Bouhissi & Sadine, 2020 (Buthidae) in North-western Algeria.

Abstract:
During nighttime in Aïn Deheb, Tiaret region (North-western Algeria). An adult female of the buthid scorpion Buthus apiatus Lourenço, El Bouhiss i& Sadine, 2020 was observed feeding on an adult Galeodessp.Such observation can contribute to the knowledge of the trophic ecology ofthis scorpion species.

Reference:
Benali N, Elkahar FMA, Boukhors AH. Natural case of predation on Camel spider (Arachnida: Solifugae) by the scorpion Buthus apiatus Lourenço, El Bouhissi & Sadine, 2020 (Arachnida: Scorpiones) in Tiaret, North-western Algeria. Revista Iberica de Arachnologia. 2024(45):159-60. [Open Access provided by author]

Thanks to Noureddine for sharing this article with me!

A very interesting article was recently published by Leo Laborieux. In this article he describes a new species of Tityus C. L. Koch, 1836 (Buthidae) from Colombia, which is the first venom spraying scorpion reported from South America.

Tityus achilles Laborieux, 2024

Venom spraying has been well documented for several scorpion species as a defense behavior and especially in the African genus Parabuthus (e.g. Parabuthus transvaalicus Purcell, 1899). Interestingly, the new species from Colombia seems to have to types of venom spraying that have different venom use: Flick and Spray. The article discusses the different behaviors and the use of prevenom (cheap) and venom (costly) in T. achilles and compares this to the existing research on venom spraying in Parabuthus. This article brings in new insight into the composition of scorpion venom(s) and the use of it.

Abstract:
Venom is a metabolically expensive secretion used sparingly in a variety of ecological contexts, most notably predation and defence. Accordingly, few animals employ their toxins from a distance, and venom-squirting behaviour is only known from select taxa. In scorpions, species belonging to two genera are known to spray venom when threatened, and previous work in Parabuthus transvaalicus shows that venom delivery depends on perceived levels of threat. Here, I describe Tityus (Tityus) achilles sp. nov., a new species of buthid scorpion from Cundinamarca, Colombia. Remarkably, this species is capable of venom spraying, a first for both the genus and the South American continent. Using frame-by-frame video analysis and ballistic equations, I show that T. (Tityus) achilles sp. nov. employs not one, but two types of airborne defences with dramatic differences in reach and venom expenditure. Further, the new species uses an unusually large reserve of prevenom-like secretion for spraying, as opposed to the costly venom used by other spraying scorpions. In light of these key specializations, I propose that toxungen spraying convergently evolved in response to different selection pressures, laying the groundwork for future investigation.

Reference:
Laborieux L. Biomechanics of venom delivery in South America’s first toxungen-spraying scorpion. Zoological Journal of the Linnean Society. 2024;202(4):zlae161. [Full text supplied by author]

Thanks to Leo and Gerard for sending me this interesting article!

Family Buthidae