A new species of Chaerilus from Malaysia

Frantisek Kovarik has recently published a new species of Chaerilus Simon, 1877 (Chaerilidae) from Malaysia.

Chaerilus alberti Kovarik, 2019

Abstract:
Chaerilus alberti sp. n. from Malaysia (Cameron Highlands) is described and fully illustrated with color photographs of preserved specimens, as well as of their habitat. Males of C. alberti sp. n. have a unique shape of chela which is stout with the manus swollen anteriorly. They are compared to other species from Southeast Asia from all of which C. alberti sp. n. differs by the shape of pedipalp chela parallel or swollen posteriorly or medially. Pedipalp chela is illustrated with color photographs of 21 of these species.

Reference:
Kovarik F. Chaerilus alberti sp. n. from Malaysia (Scorpiones: Chaerilidae). Euscorpius. 2019(274):1-9. [Open Access]

Family Chaerilidae

A new species of Centruroides from Mexico

Mexico is a hotspot for the medical important genus Centruroides Marx, 1890 (Buthidae) with appr. 45 species registered and now Javier Ponce-Saavedra and Oscar F. Francke have described a new species from Sonora State, Mexico.

Centruroides lauriadnae Ponce-Saavedra & Francke, 2019

Abstract:
Centruroides lauriadnae sp. n. is described from Sonora State, Mexico. This species belongs to the so called “striped” group in the genus (sensu Hoffmann, 1932). It is compared with the 2 other species recorded for Sonora: C. pallidiceps Pocock and C. sculpturatus Ewing, as well as compared with C. suffusus (Pocock) of northern México.

Reference:
Ponce-Saavedra J, Francke OF. Una especie nueva de alacrán del género Centruroides (Scorpiones: Buthidae) del noroeste de México. Revista Mexicana de Biodiversidad. 2019;90:e902660. [Open Access]

Family Buthidae

Scorpion pectines are probably important in finding the way home

Burrowing scorpions are usually good at finding their way home to their burrows. But how to they manage this? Gaffin and Brayford published a study late in 2017 studying the importance of the pectines in navigation. It has been well known that the pections has chemo- and mechano (vibration) sensitive sensors that are important in reproduction and prey capture, but can they also play a role in navigation?

Their study seems to confirm that the massive amount of peg sensillas on the pectins help the scorpion create a sort of chemical texture map of the area the scorpion moves in. This map can be used to quickly find the way home to the burrow after a successful prey capture.

Abstract:
The navigation by scene familiarity hypothesis provides broad explanatory power for how bees and ants navigate from the hive to distant food sources and back. The premise is that the visual world is decomposed into pixelated matrices of information that are stored and readdressed as the insects retrace learned routes. Innate behaviors in these insects (including learning walks/flights and path integration) provide the important goal-directed views to allow the initial retracing (i.e., the insect must learn the scene while moving toward the goal because everything looks different while moving away). Scorpion navigation may use a similar premise, with the chemical and textural features of the environment substituting for visual input. Scorpion pectines support thousands of chemo- and mechano-sensitive units called peg sensilla, each containing at least 10 energetically expensive sensory neurons. We have long wondered why pectines have so many pegs and associated neurons. Many sand scorpions emerge onto the surface from their home burrows at night to pursue insect prey and somehow find their way back to their burrows. Based on the measured resolution of peg sensilla, we have calculated that sufficient information exists in sand’s texture to enable scorpions to retrace previously experienced paths with little to no chance of confusion. Preliminary evidence of learning walks and path integration in scorpions is also congruent with the navigation by chemo-textural familiarity hypothesis.

Reference:
Gaffin DD, Brayfield BP. Exploring the chemo-textural familiarity hypothesis for scorpion navigation. J Arachnol. 2017;45:265-70. [Open Access]

Thanks to Matt Simon for telling me about this "old", but interesting paper that I seem to have missed when it was published!

A new species of Microtityus from Southeast Cuba

Rolando Teruel has recently published an article describing a new species of Microtityus Kjellesvig-Waering, 1966 (Buthidae) from semidesert habitats in Southeastern Cuba.

Microtityus vulcanicus Teruel, 2019

Abstract:
A new species of the buthid scorpion genus Microtityus Kjellesvig-Waering, 1966, is herein described from specimens of both sexes collected at three nearby localities in the western part of the Guantánamo Bay Area, southeast Cuba. It belongs in the "jaumei" species-group of the subgenus Microtityus (Parvabsonus) Armas, 1974 and is very peculiar not only by its external morphology (very distinct from its other Cuban congeners), but also by the unusual habitat where it occurs in and seems to be restricted to (dry and hot cactus scrub on volcanic sandy plain). The present contribution reinforces the position of this genus as the second most diverse in Cuba, with 10 nominal species.

Reference:
Teruel R. A New Semidesert Microtityus Kjellesvig-Waering, 1966 (Scorpiones: Buthidae) from Southeast Cuba, Greater Antilles. Euscorpius. 2019(273):1-15. [Open Access]

Family Buthidae

Refilling your venom glands - step by step

Scorpions use their venom for prey capture and defense. Several studies have shown that scorpions have different strategies for optimizing the venom use. The reason for this is of course because it take times to renew the venom and it is costly as the venom is a mixture of complex proteins.

Edson Norberto Carcamo-Noriega and co-workers have studied the toxicity regeneration dynamics by the scorpion Centruroides limpidus (Karsch, 1879) (Buthidae) after full venom depletion by electrical stimulation. Interestingly, the regeneration happens in steps. The normal venom volume is restored in 5 days, but the content will change in the days to come because the toxins need more time to be restored. It takes 10 days before the venom is effective against insects and it takes 13 days before the toxicity has normal levels and the venom is also effective against predators (mammals).

Abstract:
The scorpion venom is a cocktail of many components. Its composition can exhibit a level of plasticity in response to different behavioral and environmental factors, leading to intraspecific variation. The toxicity and specificity of scorpion venoms appear to be taxon-dependent, due to a co-evolutionary interaction with prey and predators, which shaped the composition at the molecular level. The venom regeneration by the venom glands is an asynchronous process, in which particular components are expressed at different stages and at different rates. According to this, it can be reasonably assumed that the regeneration of toxicity in the venom is also asynchronous. In this work, we studied the toxicity regeneration dynamics by the scorpion Centruroides limpidus after full venom depletion by electrical stimulation. For this, we evaluated the toxicity of venom samples extracted at different days post depletion, against insects (crickets) and mammals (humans, by assessing the venom activity on the human voltage-dependent Na+ channel Nav1.6). The regeneration of toxicity against humans lagged behind that against crickets (13 vs 10 days, respectively). Thirteen days after depletion the venom seems to be replenished. Our results show asynchrony in the regeneration of species-specific toxic activity in the venom of Centruroides limpidus. The understanding of the venom regeneration kinetics for the different scorpion species will help to design venom extraction protocols that could maximize the yield and quality of the collected venoms.

Reference:
Carcamo-Noriega EN, Possani LD, Ortiz E. Venom content and toxicity regeneration after venom gland depletion by electrostimulation in the scorpion Centruroides limpidus. Toxicon. 2019;157:87-92. [Subscription required for full text]

A new species of Gint from Somaliland

Frantisek Kovarik and Graeme Low recently published a new species of Gint from Somaliland.

Gint banfasae Kovarik & Lowe, 2019

The article has an updated identification key for the genus.

Abstract:
Gint banfasae sp. n. from Somaliland is described and compared with other species of the genus. Additional information is provided on the taxonomy and distribution of the genus Gint, fully complemented with color photos of specimens of both sexes of the new species, as well as of their habitat. Included is a key for Gint.

Reference:
Kovarik F, Lowe G. Scorpions of the Horn of Africa (Arachnida, Scorpiones). Part XVIII. Gint banfasae sp. n. from Somaliland (Buthidae). Euscorpius. 2019(272):1-14. [Open Access]

Family Buthidae

Bothriuridae in Asia - No more

In 1996, Wilson Lourenco described the species Cercophonius himalayensis Lourenco, 1996 (Bothriuridae) from the Himalayas of India. This was the only known bothriurid from Asia, and no other members of this family have been recorded from this region afterwards.

Andres Ojanguren-Affilastro and co-workers have now examined the holotype of Cercophonius himalayensis and conclude that it should be synonymized with the South American species Phoniocercus sanmartini Cekalovic, 1968. The authors conclude that the holotype of C. himalayensis probably was mislabeled and it was not collected in India. This also means that there are now no Bothriuridae in Asia, only in South America, Africa and Australia.

Abstract:
We studied the male holotype of Cercophonius himalayensis Louren¸co, 1996, the sole member of the scorpion family Bothriuridae from India, and concluded that it belongs to a species of the genus Phoniocercus Pocock, 1893, which is endemic to the temperate forests of Patagonia. The presence of a Patagonian genus in India is extremely unlikely; therefore, we consider this to be a case of mislabeling of the specimen, and consequently exclude the scorpion family Bothriuridae from Indian fauna. Cercophonius himalayensis is transferred to the genus Phoniocercus, and formally synonymized with Phoniocercus sanmartini Cekalovic, 1968. A brief illustrated description of the type specimen is made, emphasizing important diagnostic characters and some body parts not previously described, such as the hemispermatophore. We also present a probable explanation for the origin of the material.

Reference:
Ojanguren Affilastro AA, Volschenk ES, Mattoni CI. The identity of Cercophonius himalayensis Lourenco, 1996, and the exclusion of the scorpion family Bothriuridae from the Indian fauna. J Arachnol. 2018;46:473–80. [Subscription required for full text]

Thanks to Andres Ojanguren-Affilastro for sending me their article!

Family Bothriuridae