17 January, 2019

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]

14 January, 2019

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

10 January, 2019

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

Five new species of Brachistosternus from deserts in Chile and Peru


Andres Ojanguren-Affilastro and co-workers have published a new paper on the Brachistosternus Pocock, 1893 (Bothriuridae) fauna in deserts in Chile and Peru. Five new species are described.

Brachistosternus anandrovestigia Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Peru)

Brachistosternus contisuyu Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Peru)

Brachistosternus gayi Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Chile)

Brachistosternus misti Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Peru)

Brachistosternus philippii Ojanguren Affilastro, Pizarro-Araya & Ochoa, 2018 (Chile)

Some diagnostic characters for the genus is also discussed.

Abstract:
Five new scorpion species of genus Brachistosternus of Chile and Peru are described. Brachistosternus gayi n. sp. is a high Andean species of north central Chile. Brachistosternus philippii n. sp. occurs near the coast of Antofagasta. Brachistosternus misti n. sp. occurs at intermediates altitudes of southern Peru. Brachistosternus contisuyu n. sp. occurs in Lomas formation in southern Peru. Brachistosternus anandrovestigia n. sp. occurs in coastal areas of southern Peru, and is the second known species of the genus without metasomal glands or androvestigia. Two diagnostic characters are discussed: the Internal Laminar Apophysis of the right hemispermatophore, and the sternum macrosetae.

Reference:
Ojanguren Affilastro AA, Pizarro-Araya J, Ochoa JA. Five new scorpion species of genus Brachistosternus (Scorpiones: Bothriuridae) from the deserts of Chile and Peru, with comments about some poorly studied diagnostic characters of the genus. Zootaxa. 2018;4531(2):151-94. [Subscription required for full text]

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

Family Bothriuridae

04 January, 2019

A new species of Auyantepuia from Brazil


Eric ythier has recently published an article describing a new species of Auyantepuia González Sponga, 1978 (Chactidae) from Brazil.

Auyantepuia royi Ythier, 2018

The article has an identification key for the genus.

Editors note: The status of the genus Auyantepuia is controversial. The genus has been synonymized and reinstated several times. At the moment, the genus is not listed in an ordinary way in The scorpion Files. Old species are listed in other genera (based on the latest synonymization), while new species described in the genus after 2010 are listed under Auyantepuia as it is not possible for me to assign them to other genera.This is a temporary solution until someone publish a revision of the genus and/or the Chactidae family. Se family page for more information. The following species is listed in the genus in the current article:

Auyantepuia parvulus (Pocock, 1893) (Brazil) [Neochactas parvulus (Pocock, 1897) in SF]
Auyantepuia scorzai (Dagert, 1957) (Venezuela) [Broteochactas. scorzai Dagert, 1957 in SF]
Auyantepuia fravalae Lourenço, 1983 (French Guiana) [Neochactas fravalae (Lourenço, 1983) in SF]
Auyantepuia gaillardi Lourenço, 1983 (French Guiana) [Neochactas gaillardi (Lourenço,1983) in SF]
Auyantepuia sissomi Lourenço, 1983 (French Guiana) [Neochactas sissomi (Lourenço, 1983) in SF]
Auyantepuia kelleri Lourenço, 1997 (French Guiana) [Neochactas kelleri (Lourenço, 1997) in SF]
Auyantepuia mottai Lourenço et Araujo, 2004 (Brazil) [Neochactas mottai (Lourenço & Araujo, 2004) in SF]
Auyantepuia amapaensis Lourenço et Qi, 2007 (Brazil)
Auyantepuia surinamensis Lourenço et Duhem, 2010 (Suriname)
Auyantepuia laurae Ythier, 2015 (French Guiana)
Auyantepuia aluku Ythier, 2018 (French Guiana)
Auyantepuia aurum Ythier, 2018 (French Guiana)
Auyantepuia royi Ythier, 2018 (Brazil)

Abstract:
A new species of scorpion belonging to the Guiano Amazonian genus Auyantepuia González Sponga, 1978 (family Chactidae Pocock, 1893) is described on the basis of one specimen collected in a rainforest formation located in Oiapoque, Amapá State, Brazil. This is the thirteenth species of the genus Auyantepuia and the fourth reported from Brazil.

Reference:
Ythier E. A new species of Auyantepuia GonzálezSponga, 1978 (Scorpiones, Chactidae) from Brazil. Arachnida - Rivista Aracnologica Italiana. 2018;4(20):13-22.

Thanks to Eric Ythier for sending me his article!

Family Chactidae

03 January, 2019

A new cave-dwelling Chaerilus species from the Philippines


Happy New Year!

Wilson Lourenco and Andrea Rossi have recently published an article on the cave population of Chaerilus Simon, 1877 (Chaerilidae) from Palawan, Philippines. A new species is described.

Chaerilus agnellivanniorum Lourneco & Rossi, 2018

The biogeography of the genus in Borneo and Palawan is also discussed.

Abstract:
The study of an important collection of scorpions, belonging to the genus Chaerilus, recently collected from a cave in the Palawan Island, Philippines, allows the clarification of the identity of this population, often misidentified with Chaerilus chapmani Vachon & Lourenco, 1985 known from caves in the Gunong Mulu National Park in Sarawak (Borneo). Chaerilus agnellivanniorum sp. n. is described from the Puerto Princesa Underground River Cave in Palawan Island based on 14 specimens, males, females, and juveniles. The new species is totally distinct morphologically from Chaerilus chapmani, a true troglobitic species. Chaerilus agnellivanniorum sp. n. may also be a true troglobitic element, but with a less marked degree of regression for several characters. Some comments on the ecology of the new species and on regional biogeography of Borneo and Palawan islands are also proposed.

References:
Lourenco WR, Rossi A. The cave population of Chaerilus Simon, 1877 from Palawan, Philippines, and description of a new species (Scorpiones: Chaerilidae). C R Biol. 2018. In Press. [Subscription required for full text]

Family Chaerilidae

20 December, 2018

2018 Season's Greetings from The Scorpion Files