Parabuthus transvaalicus
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Parabuthus transvaalicus , male |
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| Purcell , 1899 |
Parabuthus transvaalicus , also known as the South African thick-tailed scorpion , is one of the largest scorpions of the species-rich family Buthidae and reaches a body length of 12 to 16 centimeters (including tail). The specific epithet transvaalicus refers to its distribution area in southern Africa.
etymology
Zoological name
Parabuthus transvaalicus was first described in 1899 by William Frederick Purcell as one of 33 species of the genus Parabuthus known today . Purcell (1866-1919) was a South African zoologist from England who made a name for himself as a pioneer in the study of arachnids . He described numerous species of scorpions and spiders - including genera such as Harpactirella . Purcell derived the specific epithet from the name Transvaal Republic for the area of the then South African Republic and today's South African province Transvaal . In this area ( Terra typica ) the species was apparently first discovered by Purcell.
German name
The German term "South African Dickschwanzskorpion" is used less often in common parlance; the scientific name is preferred. The common name thick- tailed scorpion (English fattail scorpion ) is mainly used for species of the genus Androctonus , which have a uniformly thick abdomen. However, in Parabuthus transvaalicus too, it points to its relatively broad, five-segment metasoma (tail part) with the (for the Buthidae family) unusually thick telson (with a large venom gland). This broad physique is even more evident in the males due to their smaller size, as the ratio between scissorhands and tail varies more.
description
With an average size of ten to twelve centimeters, the females are more powerfully built than the males, who often only reach seven to ten centimeters. Parabuthus transvaalicus reaches a maximum total length of 16 centimeters and is thus the second largest species of the genus after Parabuthus villosus . Regardless of gender, the scorpion is uniformly colored from chestnut brown to blackish gray. In the tail area (metasoma) there is a longer, red-brown to black-colored comb hair, the pink shimmering plural skin and a strong grain on the surface of the chitin armor. These conspicuous unevenness in individual tail segments lead as keels in rows up to the telson . The tail area and telson are roughly the same thickness and black-gray to red-brown in color. The treadmills attached to the mesosoma (middle area) and the scissors hands ( pedipalps ) attached to the prosoma (front area ) are, however, often lighter amber-brown in color.
In addition to the difference in size, a sexual dimorphism becomes noticeable , as in all members of the Buthidae family, in the male in longer comb organs (pectuses) and comb teeth on the underside (tactile organs). The connecting pieces between the comb organs, so-called basal links , are smaller or shortened. In the male, 37 to 42 comb teeth were counted as a rule; the female has only between 33 and 36. In addition, male animals usually have shorter, but thicker, rounded claw hands. A sex determination of Parabuthus transvaalicus can usually already be done in the second instar by counting the comb teeth. However, the full differentiation of the sexes is only achieved in the adult stage.
distribution
Parabuthus transvaalicus has its distribution center in southern Africa. So far, its occurrence in South Africa , Botswana , Mozambique and Zimbabwe has been proven. The scorpion is found particularly frequently in South Africa between Cape Town and Pretoria , in the former Transvaal regions ( transvaalicus ) and in the Cape Country . The related species Parabuthus capensis and Parabuthus granulatus also live there .
habitat
Parabuthus transvaalicus lives mainly in subtropical arid climates, especially in semi-deserts , scrubland and steppe regions , which have sparse vegetation. Its habitats are usually subject to strong temperature fluctuations between day and night. Within its habitat, the South African thick-tailed scorpion can be found relatively often under weathered wood, roots or rubble.
The habitats of Parabuthus transvaalicus usually make agricultural use almost impossible due to the lack of moisture. Therefore, the scorpion usually only occurs in areas with little population and so rarely comes into contact with people. Only in isolated cases does the species penetrate into inhabited areas and into houses.
Way of life
Parabuthus transvaalicus is one of the burrowing scorpion species and creates longer tunnels in the sandy soil overnight. During the hottest time of the day, it stays in such caves or under stones in the shade and is therefore nocturnal if you avoid rigor during the day. In contrast to the males, which only leave their quarters at dusk, the females are also active during the day.
The South African thick-tailed scorpion feeds on insects and smaller mammals that it paralyzes or kills by transmitting poison through a sting . In the case of food shortages, cannibalism often occurs , with females often eating the physically inferior males. When disturbed, Parabuthus transvaalicus changes to the threatening posture typical of scorpions and does not hesitate to stab.
In Parabuthus transvaalicus is a solitary living scorpion who seeks a mate only to mate. It defends its territory aggressively against conspecifics, so that same-sex animals can only live together if there is sufficient food available.
Reproduction and development
→ Main article: Scorpions
Mating behavior
The mating behavior of Parabuthus transvaalicus is similar to that of other scorpions and takes place in the form of a mating dance. The male leaves his hiding place and follows the pheromone scent trail of a female. As soon as the male has found his partner, it begins to tremble at the metasoma and the pedipalps and grabs the female by the scissor hands. The “wedding dance” that follows, in which the animals move back and forth and in circles, can last a few minutes or up to two hours. The male uses the comb organs to look for a suitable place to deposit the approximately 12 millimeter large, brownish-looking spermatophores . After the female has been led across the storage area and has picked up the sperm container, the partners suddenly separate. The consumption of the male by the female, as is common with some scorpion species after mating, does not usually occur in this species. An individual can mate several times in his life.
development
After a gestation period of eight to twelve months, during which the mother needs a lot of food, between 20 and 100 young animals are born alive ( viviparia ). In a natural environment, the number of births is reduced to an average of 32 pups due to external factors such as threat or stress. When kept in a terrarium , between 60 and 100 white nymphs often develop .
After the cubs climb onto the mother's back, they stay there for three to four days. After their subsequent first molt, another three to four days pass on the female's back, during which the chitin shell hardens. Now they are able to go looking for food, but only relatively small prey animals can be captured. When food is scarce, cannibalism often occurs among the young. The last moult takes place after one year and the animals reach sexual maturity. Depending on the food supply and the ambient temperature, this can, however, be delayed for two years.
Venom from Parabuthus transvaalicus
Parabuthus transvaalicus is one of the most poisonous scorpions in Africa, whereby the danger of its poison is not in the strength, but in the amount. Due to its exceptionally large poisonous bladder, it can release a great deal of it in a short time and also reproduce quickly. Up to 14 milligrams of dry weight of the toxin were obtained in one dose. Due to the large quantity of poison, the South African thick-tailed scorpion is classified as a human pathogenic species on the one hand and a sting-prone and defensive species on the other, so that careful handling of the animals must be guaranteed.
Parabuthus transvaalicus has the ability to actively regulate the composition of its venom. The so-called prevenom is only used in the event of minor irritation, for example from a smaller prey, with a paralyzing effect. It contains proteins such as birtoxin , dortoxin , bestoxin and altitoxin , which cause cardiac muscle paralysis, are only present in low concentrations. Such a transparent-looking secondary poison is also used during mating, whereby the male stings the female, presumably to calm her down.
The milky-white, stronger poison is injected as a defense against larger vertebrates . This is composed primarily of neurotoxins such as acetylcholine or sympathomimetics such as endogenous catecholamines . A species-specific substance called kurtoxin was also isolated. The sting can cause severe pain as well as cardiac and central nervous symptoms , even in humans . When the toxin is administered subcutaneously to mice, the measured lethal dose (LD 50 value) is 4.25 milligrams of poison per kilogram of body weight . The poison may even be life-threatening, especially for children and the elderly, but also for adults. The deaths known to date were mainly caused by failure of breathing . In addition, the scorpion is able to spray its poison over a meter ( spitting scorpion ), which also threatens the eyes. He can literally squirt it outwards via his muscular telson and the sting.
If there are stab accidents, a doctor or a clinic should be consulted immediately and the description or the name of the scorpion should be available. In the event of pain, a local anesthetic can be infiltrated . Patients with breathing disorders must be intubated and ventilated, after which further measures can be taken depending on the symptoms. There is already an antidote , but its effect is controversial and should only be given with the recommendation of a poison information center. According to the literature , the administration of morphine , pethidine , barbiturates , calcium supplements , corticoids and atropine should also be avoided.
Systematics
In addition to the South African thick-tailed scorpion, another 32 species and 17 subspecies have been described in the genus Parabuthus . No subspecies are known for Parabuthus transvaalicus . However, it shows a striking, outward resemblance to its sister species Parabuthus villosus . As far as we know today, both of them stand opposite Parabuthus schlechteri and Parabuthus raudus . The four species together are again compared to Parabuthus kraepelini . At the geozoological level, the sister species Parabuthus villosus lives in close proximity to Parabuthus transvaalicus . In addition to South Africa, it is also native to Namibia and Angola .
An exact phylogenetic classification of Parabuthus transvaalicus is shown here .
References
- ↑ a b Lorenzo Prendini, Lauren A. Esposito: A reanalysis of Parabuthus (Scorpiones: Buthidae) phylogeny with descriptions of two new Parabuthus species endemic to the Central Namib gravel plains, Namibia . Zoological Journal of the Linnean Society 159 (3), 2010, pp. 673-710
- ↑ a b c d Jan Ove Rein: Parabuthus transvaalicus (Purcell, 1899) In: The Scorpion Files , status: 2007 (accessed: May 14, 2007)
- ^ A b c Vincent Carruthers: Spiders and other arachnids. The Wildlife of Southern Africa: a Field Guide to the Animals and Plants of the Region ( Memento of May 14, 2014 in the Internet Archive ) . Struik, 2003, pp. 14-27. ISBN 978-1-86872-451-2
- ^ A b Giorgio Molisani: Parabuthus transvaalicus In: Poecilotheria.com. Experience reports , status: July 17, 2005 (accessed: May 26, 2006)
- ^ A b Jonathan Leeming: Scorpions of South Africa. New Holland Publishers, Cape Town 2003, pp. 3-88. ISBN 1868728048
- ↑ a b c Ralf Rebmann: Parabuthus spp., With the focus on medically important species
- ↑ Bora Inceoglu, Jozsef Lango, Jie Jing, Lili Chen, Fuat Doymaz, Isaac N. Pessah & Bruce D. Hammock: One Scorpion, two venoms, Prevenom of Parabuthus transvaalicus acts as an alternative type of venom with disting mechanisms of action. in: Proceedings of the National Academy of Sciences of the United States of America 100 (3), 2003, pp. 922-927. ISSN 0027-8424
- ↑ Serguei S. S? I, Isabelle M. Mintz: Kurtoxin, a gating modifiers of neuronal high- and low threshold Ca channels . The Journal of Neuroscience 22 (6), 2002, pp. 2023-2034.
- ↑ Chul Won Lee, Chanhyung Bae, Jaeho Lee, Jae Ha Ryu, Ha Hyung Kim, Toshiyuki Kohno, Kenton J. Swartz, Jae Il Kim: Solution Structure of Kurtoxin: A Gating Modifier Selective for Cav3 Voltage-Gated Ca2 + Channels . Biochemistry 51 (9), 2012, pp. 1862-1873. PMC 3295331 (free full text)
- ↑ Carine J. Marks, et. al .: The epidemiology and severity of scorpion envenoming in South Africa as managed by the Tygerberg Poisons Information Center over a 10 year period . In: African Journal of Emergency Medicine . tape 9 , no. 1 . Elsevier, Amsterdam 2019, p. 21–24 , doi : 10.1016 / j.afjem.2018.12.003 .
- ↑ Lorenzo Prendini: Discovery of the Male of Parabuthus muelleri, and Implications for the Phylogeny of Parabuthus (Scorpiones: Buthidae) . American Museum of Natural History 3408, 2003, p. 6
literature
- Dave Gaban: Gaban's scorpion tales. On: Parabuthus transvaalicus (Purcell) . Forum of the American Tarantula Society, 6 (5), 1997, pp. 157-158.
- Dieter Mahsberg, Rüdiger Lippe, Stephan Kallas: Scorpions . Münster 1999. ISBN 3-931587-15-0
- Eliahu Zlotkin, François Miranda, Hervé Rochat: Venoms of Buthinae. C, Chemistry and pharmacology of Buthinae scorpion venoms. 1976, pp. 317-369. In: Sergio Bettini (ed.): Arthropod Venoms. Handbook of experimental pharmacology 48, Springer-Verlag: Berlin 1978. ISBN 978-3-642-45503-2 (print), ISBN 978-3-642-45501-8 (online)
- Gerald Newlands: The venom-squirting ability of Parabuthus scorpions (Arachnida: Buthidae) . South African Journal of Medical Sciences 39, 1974, pp. 175-178.
- Giorgio Molisani: Parabuthus transvaalicus . In: Reptilia . Desert scorpions 53, 2005, pp. 37-39. ISSN 1431-8997
- Giorgio Molisani: keeping and breeding of Parabuthus transvaalicus Purcell. 1899 . In: Arachne 10 (6), 2005, pp. 4-10. ISSN 1613-2688
- Lorenzo Prendini: Phylogeny of Parabuthus (Scorpiones, Buthidae) (PDF; 1.3 MB) . Zoologica Scripta 30 (1), 2001, pp. 13-35.
- Lorenzo Prendini: The systematics of southern African Parabuthus (PDF; 3.5 MB) . The Journal of Arachnology 32, 2004, pp. 109-186.
- Manny Rubio: Scorpions - A complete pet owner's manual. Barrons, New York 2000, pp. 2-95. ISBN 0764112244
- Nils Johannes Bergman: Clinical description of Parabuthus transvaalicus scorpionism in Zimbabwe . In: Toxicon 35 (5), 1997, pp. 759-771. ISSN 0041-0101
- William Frederick Purcell: New South African scorpions in the collection of the South African Museum . Annals of the South African Museum 1, 1899, pp. 433-438.
