Opistophthalmos

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Opistophthalmos
Opistophthalmus glabrifrons

Opistophthalmus glabrifrons

Systematics
Trunk : Arthropod (arthropoda)
Sub-stem : Jawbearers (Chelicerata)
Class : Arachnids (arachnida)
Order : Scorpions (Scorpiones)
Family : Scorpionidae
Genre : Opistophthalmos
Scientific name
Opistophthalmos
CL Koch , 1837

Opistophthalmus is a genus of the family Scorpionidae within the order Scorpions that is distributed in southern Africa and with two species in East Africa. It is the most species-rich and the only genus of the Scorpionidae in its range. With around 60 species in a relatively limited area, it is very diverse. Many of their species only have a very small distribution area of ​​a few square kilometers.

Almost all representatives of opistophthalmus live in self-dug apartment tubes, which they rarely leave. Many have developed physical adaptations to the habitats they inhabit. This includes a flattened body in rock-dwelling species, some of which do not dig dwelling tubes, but only expose shallow cavities under stones. The sand dwellers have thick hair on their legs, which makes it easier for them to throw sand away when digging their burrows. Far-reaching adaptations are shown by those species that dig their living tubes in hard clay soil. They have particularly strong chelicerae with which they remove the hard soil in small pieces. As in Opistophthalmus glabrifrons, your eyes are shifted far back in order to create space for the muscles of the chelicerae in the prosoma .

Some physical features of opistophthalmos are unique to scorpions, such as the stridulation and chemoreception organs on the chelicerae. In addition, some species have an exceptionally high number of trichobothria on the pedipalps , others a very low number of comb teeth on the comb organs .

features

Opistophthalmus pallipes , female on the left and male on the right

The species of the genus Opistophthalmus vary greatly in size. With the 160 mm long Opistophthalmus gigas one of the largest and with the 40 mm long Opistophthalmus pygmaeus the smallest member of the family Scorpionidae belong to them . The species have different colors, from uniformly dark brown or black to uniformly pale yellow. In addition, there are numerous species with a dark basic color, in which the sternum , metasoma , individual tergites , the telson , legs, pedipalps or chelae are brightly colored. The sexual dimorphism is often very pronounced.

In Opistophthalmus, the carapace has only a shallow indentation at the front edge, which is completely absent in some species. In the pandinus and heterometrus this indentation is deeply cut in a U-shape. Be on the carapace three side ( lateral ), however, pairs of eyes in a few species only two. The midline ( median ) pair of eyes can be shifted from the center to the front or, for example in opistophthalmus glabrifrons , extremely far back. The sternum is longer than it is wide, and in most cases it is pentagonal. There are often unusual surface structures on the sternites and on the undersides of the first four limbs of the metasoma. The keels (Carinae) that are almost always present on the metasoma of the scorpions are only weakly developed in opistophthalmos or they are absent entirely. The teeth of the comb organ are short and curved, and only in the males of a few species are long and straight. Some species have an unusually low number of teeth on the comb organs, including in one case the lowest number recorded in any species of scorpion.

At the Coxen the Cheliceren most species have both sexes two forms of setae that the Stridulation and Chemoreception serve. These organs are not found in other genera of scorpions. The fingers of the Chelae are smooth and only have granules in a few species. There are no stridulation organs on the coxae of the pedipalps and the first pair of legs. Some species have an exceptionally large number of Trichobothria on the Pedipalps.

Almost all species of the genus Opistophthalmus have developed morphological adaptations to the habitats they inhabit, which offer them advantages when moving on sand or when digging in hard ground. These adaptations are extremely pronounced in the species Opistophthalmus flavescens and Opistophthalmus holmi that live on shifting dunes . The claws on the tarsi are greatly enlarged, their rear legs have a brush-like appearance because of the numerous setae , and their comb organs are reduced in size, with a greatly reduced number of comb teeth. Other species prefer rocky habitats. The males of species such as Opistophthalmus austerus , Opistophthalmus karrooensis and Opistophthalmus pallipes expand crevices under or between rocks. Their physique is adapted to this way of life by the fact that prosoma and mesosoma are strongly flattened compared to other species.

Opistophthalmus glabrifrons digs its living tubes into hard loamy substrate. He does not use his chelae to dig but loosens the material with his enlarged chelicerae and uses his hind legs to push it out of the tube. Accordingly, the chelicerae muscles are strongly developed and take up a lot of space in the anterior prosoma. This fact was used to explain the shift of the medial pair of eyes backwards. The legs of these species that dig in hard ground are shorter and stronger, with short claws and strong macroset on the tarsi .

distribution and habitat

Kalahari , Namibia, sandy desert as a habitat for psammophilic species
Small Karoo , South Africa, semi-desert as a habitat for the pelophilic species
Brandberg massif , Namibia, rocky habitat of the lithophile species

Opistophthalmus is common in southern Africa up to the 15th parallel and with two species up to Kilimanjaro in East Africa. It is the only genus of the Scorpionidae family in its range. Find reports of species of the genus Pandinus contained in the older literature were incorrect. Within this range, the genus Opistophthalmus, with around 60 described species, represents more than 40% of the scorpion species living there. This puts it here as the most extensive taxonomic group in front of the entire Buthidae family, which is known to be rich in species .

The scorpion fauna of southern Africa consists mainly of species with a small range. The genus Opistophthalmus is no exception, almost half of its species colonize areas of less than 500 square kilometers. For the distribution of the types of Opistophthalmus it is considered crucial that they are predominantly bound to habitats with a certain soil quality. The hardness of the substrate is more important than its composition. Some of the pelophilic ( clay- loving or clay- dwelling ) species, Opistophthalmus boehmi , Opistophthalmus carinatus, and Opistophthalmus glabrifrons , have very large ranges compared to their psammophilic (sand-dwelling) relatives. This is explained by the fact that their acquired ability to dig in hard substrate allows them to colonize a wider range of habitats .

The species of the genus live mainly in the dry western part of the region across the range. Only a few colonize dry areas in the east such as the South African provinces of Eastern Cape and Limpopo . Often they are tied to mountainous and rocky habitats.

Within some areas, different species of the genus Opistophthalmus occur together, which differ significantly in the size of the adult animals. This applies in the Namib Opistophthalmus flavescens and Opistophthalmus Holmi , and in the Kalahari Opistophthalmus concinnus and wahlbergii Opistophthalmus . This fact, which is also known from species of the genus Hadogenes , is justified by the fact that there is less food competition at least for adult specimens as predators of different sized prey animals. This is countered by the fact that there must be phases during growth in which individuals of the same size of different species appear together.

Another attempt to explain the occurrence of closely related species in the same area cites the preferred hardness of the soil as the reason for decreased competition between the species concerned. Opistophthalmus concinnus digs its caves in limestone , and Opistophthalmus wahlbergii prefers loess soil . The preferred location of the burrows also seems to be important. Opistophthalmus granifrons lives with Opistophthalmus peringueyi and Opistophthalmus boehmi with Opistophthalmus lawrencei in the same area. While the former dig their burrows at the foot of Inselbergs in sandy loam, the others seek shelter under stones.

Way of life

Entrance of a living tube of Opistophthalmus pugnax , with the open inlet

The types of Opistophthalmus are divided into lithophilic (living on stones), pelophilic (living on clay) or psammophilic (living on sand). Not a single species is a forest dweller who takes shelter under tree bark, and there are no cave dwellers either. The lithophilic species such as Opistophthalmus karrooensis and Opistophthalmus pallipes live in rocky landscapes, some of them have lost the ability to build living tubes and seek shelter under stones.

The pelophilic species - they include Opistophthalmus boehmi and Opistophthalmus glabrifrons - dig their living tubes in loam or clay, which is often mixed with sand, strongly compacted and hardened. In contrast to the sand inhabitants, they do not dig with the pedipalps, but with the chelicerae. Digging has been described in detail for several species. The material loosened with the chelicerae is thrown backwards and out of the tube with the first two pairs of legs, while the two rear pairs of legs provide the necessary support. With the two pedipalps, the scorpion usually leans forward to avoid tipping over. Occasionally they are also used to shovel away soil. Moist earth, the movement of which requires greater effort, is also moved by the fact that the scorpion runs backwards in the tube and pushes the material back a little with each step. The metasoma is also used in the construction of antechamber for burrows to push the earth away. To do this, the scorpion curves its metasoma to the side and pushes the material away with subsequent stretching.

The psammophilic species belong to the highly specialized species. Opistophthalmus flavescens and Opistophthalmus holmi live on shifting dunes and dig their burrows in sand. They not only serve them as a hide to lie in wait for prey, but also as a way of retreating from the extremely high ground temperatures.

Residential tubes

Almost all species of the genus Opistophthalmus live at least as young animals in living tubes that have been dug under stones or in open spaces. Since the scorpions of the genus have a strong tendency to cannibalism, the burrows - apart from the mating season and during brood care - are always inhabited alone. The entrances of the living tubes can easily be distinguished from those of the burrows of other burrowing animals due to their oval, kidney or sickle-shaped design, which is typical for members of the Scorpionidae family. Inhabited buildings often have a wall of heaped earth at the entrance, which helps prevent rainwater from flowing in. Some species only dig shallow, short tubes, while others dig long, spiraling tunnels that extend to a depth of more than a meter.

The living tubes of Opistophthalmus capensis have been the subject of detailed investigations. This scorpion digs its living tubes under stones. Under the stone, which can have a diameter of 15 to over 60 cm, an inlet is excavated on the surface of the ground, which in most cases is expanded into an antechamber shortly before the entrance of the residential tube. The living tube leads downwards at an angle of about 40 degrees and ends after about 20 cm with a slight widening to a final chamber. Male animals often limit themselves to very short living tubes, or they only create an inlet. The antechamber is the usual place of ingestion; food remains were rarely found in the final chambers of the living tubes. The psammophilic species Opistophthalmus flavescens digs 30 to 50 cm deep living tubes in the solidified sand on the slopes of dunes.

A female of Opistophthalmus pugnax , with older young on her back

Often the young animals leave the den of the mother in which they grew up, dig their own living tube in the immediate vicinity, only one or two centimeters long and expand it further and further as they grow. The fact that the following generations remain at their place of birth, often without ever changing the structure, leads to high local population densities in some species.

The burrows or shelters of Opistophthalmus play a central role in the life of animals. Here feeding, molting, courtship , mating, the birth of the young and their rearing take place. To catch food, the animals go to the entrances of their living tunnels, await potential prey as ambulance hunters and pounce on them. The killed prey is then pulled into the burrow for consumption. Only during the mating season in spring, i.e. September to November, do the males leave their burrows to look for a female ready to mate. In turn, courtship and mating take place in the den of the female animal.

Mating behavior

Up until the middle of the 20th century, scorpions had never fully mated, and it was believed that there was an act of copulation with internal fertilization. Independent observations of the mating of scorpions of the genus Centruroides and Opistophthalmus latimanus in terrariums led to the finding in the mid-1950s that mating ends with the transfer of a spermatophore . It was also observed for the first time that the male pulls his partner towards him immediately before the start of the mating dance with the pedipalps, grabs and holds her chelicerae with his chelicerae, and loosens the grip of the pedipalps. What role this detail, known only from a few scorpions apart from opistophthalmos , is unclear.

Prey and feeding behavior

Cockroach Temnopteryx phalerata
Drivers ant Dorylus helvolus , attacked by smaller ants.

The range of prey includes predominantly articulated animals , including other scorpions. Cannibalism, especially to the detriment of young animals, is a normal phenomenon. Opistophthalmus capensis was observed in the natural environment when the driver ant Dorylus helvolus and the cockroach Temnopteryx phalerata were hunted . Animals in the laboratory held this type also took American big cockroaches , coreidae , scorpions the type Uroplectes lineatus , pill bugs , scarab beetles , beetle larvae, moths and their larvae readily as feed animals on. Centipedes , bipedes and ground beetles of the genus Anthia , however, were spurned. Scorpions occasionally overwhelm prey other than arthropods. For Opistophthalmus carinatus , the consumption of sea ​​slugs has been documented, but in laboratory tests, insects were preferred when they were available. The same species has been seen eating a young gecko that accidentally got into the scorpion's den.

In Opistophthalmus capensis , pellets made from leftover food were found in the chambers of excavated living tubes. They mainly consisted of indigestible wings and legs of black beetles and cockroaches. Laboratory observations on feeding behavior could be made for several species. Small prey are captured with the chelae , lifting the metasoma but not stinging the prey. In the case of larger prey, the scorpion slowly moves its metasoma with the telson sideways to the prey and looks for suitable places for the injection of the poison. Only large and defensive prey is overwhelmed in such a way that the scorpion adopts an attacking stance, leads the metasoma forward over the body and stings the prey a number of times. This behavior differs from that of the Parabuthus species, which are also widespread in southern Africa , in which the poison apparatus is primarily used to defend and overwhelm prey. After overpowering the prey, the scorpion immediately starts consuming it and needs one to three hours in the laboratory, depending on the size of the prey.

Predators

Meerkat eating a frog, Namibia
Southern fiscal strangler with captured cricket.
Barn Owl , Gauteng Province , South Africa

Bear baboons , aardwolves , African civets , meerkats and honey badgers are known to be predators of scorpions of the genus Opistophthalmus . The meerkats are considered to be largely insensitive to scorpion venom , but they show different behavior in relation to captured scorpions of the genera Parabuthus and Opistophthalmus . In the highly poisonous Parabuthus species, they remove the telson early with the poison sting , while in opistophthalmos they tear off the pedipalps with the powerful scissors. For the honey badger it could be determined in a field study that digging up scorpions is unattractive compared to that of mammals and reptiles because of the low biomass of the prey animals. It only took place to a significant extent during the cold and humid season when there was a lack of other prey such as small mammals and bee larvae. Even then, scorpions, almost exclusively Opistophthalmus wahlbergii in the field study , only made up a small proportion of the diet of honey badgers. However, the number of scorpions consumed was considerable, with almost 200 scorpions among the more than 2,000 eaten prey.

It was only in the middle of the 20th century that it was recognized that bats can pick up prey from the ground. The Egyptian slit nose , which is also widespread in southern Africa, was one of the first species for which evidence of the capture of ground-dwelling arthropods was provided. In Namibia, a farmer found droppings and remains of food every day that contained parts of Opistophthalmus wahlbergii up to almost complete scorpions. Later long-term observations at feeding grounds of the Great Slit Nose could not confirm a particularly large proportion of scorpions in their diet. The composition of their diet, however, varies greatly from one year to the next, and it has been observed that the diet sometimes consisted of frogs or bats over a longer period of time, depending on their availability.

Among the birds there are reports of the consumption of scorpions by Bokmakiris and the Southern Fiscal Shrike . Due to their consistent nocturnal activity, owls are also important predators. For the Fleckenuhu , the barn owl and the African grass owl , the preying of scorpions has been proven by the investigation of tarns . In the Namib, there have been finds of barn owl dunes, the components of which were predominantly the remains of scorpions.

Smaller types of opistophthalmos and juveniles of larger types belong to the prey spectrum of other scorpions, including their adult conspecifics. They often avoid encountering these predators lying in wait at the entrance of their living tubes or hunting on the ground by going to the vegetation themselves to forage.

Parasites

Overall, the parasite fauna of the scorpions has been poorly researched. In an investigation of scorpions from seven described and four previously undescribed species of the genus Opistophthalmus , it was found that all the animals examined were infected with the parasitic Wolbachia bacterium . In five scorpions that could strains of Wolbachia be determined. Each scorpion was infested with only one strain, and all five carried different strains. The strains are closely related and likely form a monophyletic group. Within the Wolbachia system , they belong to the geographically widespread but not particularly frequent super group F. It is currently unclear whether infections with Wolbachia -F are more common among scorpions or whether they are a peculiarity of opistophthalmos .

Danger

Terrarium photo of Opistophthalmus glabrifrons

The destruction of their habitats through agriculture, deforestation and urbanization is the greatest threat to species of the genus Opistophthalmus, which are characterized by their strong adaptation to special habitats and their sometimes very small distribution areas. One species seems to be extinct. Other species, particularly endemic species in South Africa's Western Cape Province , are considered critically endangered.

Several species, including Opistophthalmus glabrifrons and Opistophthalmus wahlbergii, have long been marketed in the European, North American and Japanese terrarium trade with the alleged country of origin Mozambique. Opistophthalmus wahlbergii does not occur in Mozambique, the specimens from the terrarium trade match in their morphology with the form common in the border area between South Africa and Zimbabwe as well as in eastern Botswana. It is very likely that the animals are illegally caught and exported. It is common practice in South Africa and its neighboring countries to label illegally caught scorpions with false indications of their origin. Two other species, Opistophthalmus boehmi and Opistophthalmus carinatus, were also identified in the terrarium trade. For Opistophthalmus latimanus there was even a report on keeping it in a terrarium in a Czech magazine for aquarium enthusiasts .

Systematics

External system

At the beginning of the 21st century, the Scorpionidae family consisted of four genera common in Africa and Asia, Heterometrus , Opistophthalmus, Pandinus and Scorpio . Since then, the phylogeny and taxonomy of this family have been controversial.

Systematics according to Soleglad and Fet

In 2003, the American arachnologists Michael E. Soleglad and Victor Fet from Marshall University published numerous changes to the higher systematics of the scorpions. So they declared the predominantly New World Diplocentridae family to be synonymous with the Scorpionidae. In another publication in 2005, the Urodacidae family was synonymous with Scorpionidae. Following strong criticism from several colleagues, the authors around Soleglad reaffirmed their decisions on taxonomy. Since Soleglad and Fet wrote the last publication on this topic at the end of 2005 with this rejection of the criticism, their position is formally valid today. However, the dispute over this is not over. Some subsequent authors actually considered no longer existing families to be valid. According to Soleglad and Fet, the Scorpionidae family comprises 20 genera, including Opistophthalmus .

Systematics according to Prendini, Ward and Wheeler

Scorpionidae according to Prendini, Ward & Wheeler 2003
  Scorpionidae  

 Opistophthalmos


   

 Scorpio


   

Pandinus


   

Heterometrus





Lorenzo Prendini, Timothy M. Ward and Ward C. Wheeler of the American Museum of Natural History in New York City propose that opistophthalmos forms the monophyletic family Scorpionidae with the genera Scorpio , Pandinus and Heterometrus . Within this clade , opistophthalmos is the most original genus. In an unusually sharp response to the publication of Soleglad and Fet in 2003, Prendini and Wheeler disputed the validity of the changed system in 2005 and temporarily restored the original system.

The originality of Opistophthalmus had already been recognized in 1925 by the South African zoologist John Hewitt ; it was confirmed in 2003 by an extensive DNA sequence analysis of species of the Scorpionidae family. Opistophthalmus forms a clade with Scorpio , which has already been separated from the clade with Pandinus and Heterometrus in eastern Gondwanaland . A period from the Eocene to the late Pliocene is assumed for the development of the numerous types of opistophthalmos , during which the climate in southern and eastern Africa became hotter and drier.

In a more recent work by Prashant P. Sharma and colleagues from 2015, these authors came to the conclusion that the families Scorpionidae and Hormuridae are paraphyletic to one another. A representative of the type genus Scorpio would therefore be closely related to Opisthacanthus madagascariensis (Hormuridae). The genus Opistophthalmus itself was not tested. Since the authors refrained from a taxonomic revision, not least because of insufficient taxon coverage, the status of the families is currently in doubt.

Initial description

Plate VI from the overview of the arachnid system by Carl Ludwig Koch , 1837. Above right wrong caption "Atreus". Comparison of the eye positions: those of "Atreus" (ie opistophthalmos ) particularly far back.

The genus was described in 1837 by Carl Ludwig Koch in his overview of the arachnid system . In his description, Koch placed Opistophthalmus with the genus Buthus in the Buthis family, in which he summarized the eight-eyed scorpions. To differentiate the families and the genera from one another, Koch only used the number and positions of the eyes as a diagnostic criterion. As a type species , Koch specified Opistophthalmus capensis , described by Johann Friedrich Wilhelm Herbst in 1800 as Scorpio capensis . In 1800, Herbst had made three type specimens the basis of his species description, two from his own collection and one from the collection of the German entomologist Peter Ludwig Heinrich von Block . During a revision of the species Opistophthalmus capensis , the South African arachnologist EB Eastwood found in 1977 that the syntypes have disappeared. Therefore Eastwood described a neotype for Opistophthalmus capensis . The type specimen with three toponeotypes is in the collection of the Iziko South African Museum , one toponeotype each is kept in the Natal Museum and in the Berlin Museum of Natural History .

etymology

The generic name is a compound from the Greek terms ὄπισθε opisthe for "behind" and ὀφθαλμός ophthalmos for "eye". With this, Koch referred to the fact that in opistophthalmos the medial pair of eyes is far back.

Synonyms

Opistophthalmus capensis (Illustration from the natural system of unfledged insects by Johann Friedrich Wilhelm Herbst , 1800)
  • Atreus Koch , 1837: In the first description of Opistophthalmus, the generic name Atreus was mistakenly placed as a caption under a drawing on a board with the arrangement of the eyes of different genera of the scorpions. Due to a reference from the text, it is beyond doubt that “Atreus” is opistophthalmus . Oscar F. Francke correctly identified the error as Lapsus calami , but indicated it as the supposedly correct genus Isometrus .
  • Miaephonus Thorell , 1876: Tamerlan Thorell placed the newly described species Miaephonus wahlbergii ( Opistophthalmus wahlbergii ) in this new genus in 1876 . The genus was declared a synonym for opistophthalmus by Karl Kraepelin in his major revision of the scorpions in 1894 .
  • Mossamedes Simon , 1888: in the same publication as Petrovicus furcatus , Eugène Simon also described Mossamedes opinatus ( Opistophthalmus opiatus ). Like Petrovicus, the genus Mossamedes should be an intermediate form of Heterometrus and Opistophthalmus , but with other distinguishing features. In his revision of the scorpions of 1893, Pocock made Mossamedes a synonym for Miaephonus .
  • Oecopetrus Pocock , 1893: The genus described by Karsch in 1879 as Petrooicus was renamed by Pocock in 1893 to Oecopetrus , because Petroicus was already assigned as a genus name in the Schnäpper family of the order passerine birds . This decision was only recognized as wrong in 1985 by Francke, who pointed out that Petrooicus and Petroicus were quite different names. In 1899 Kraepelin declared Oecopetrus a synonym for Opistophthalmus .
  • Opisthophthalmus Peters , 1861: the selected cooking notation was by subsequent authors, the first time in 1861 by Wilhelm Peters in the first description of Opistophthalmus glabrifrons, as defective Latinization by Opisthophthalmus replaced. Numerous other authors followed, so that the older literature mainly contains this notation. Oscar F. Francke rejected the amendment in 1985 as an unfounded emendation . In the recent literature, the genus is mainly Opistophthalmus called the spelling Opisthophthalmus but appears occasionally on.
  • Petrooicus Karsch , 1879: the scorpion described by Wilhelm Peters in 1861 as Heterometrus carinatus ( Opistophthalmus carinatus ) was transferred to the new genus Petrooicus by Ferdinand Karsch in 1879 . As a justification, Karsch pointed out the position of the median pair of eyes, which on the cephalothorax is only slightly behind the center. In his opinion, the scorpion thus took an intermediate position compared to Heterometrus and Opistophthalmus , which justified the establishment of a new genus. the genus was renamed in 1893 by Reginald Innes Pocock in Oecopetrus .
  • Petrovicus Simon , 1888: when this generic name was published in 1888, Eugène Simon believed that he was following the decision of his colleague Karsch, who had described Petrooicus in 1879 . However, with Simons misspelling in the first description of his Petrovicus furcatus ( Opistophthalmus furcatus ), a new generic name was introduced into the system. Simon is considered an author because he used the name in 1888 as part of a species description. The fact that the Austrian arachnologist Anton Ausserer published the same typographical error as early as 1880 is irrelevant, since he only cited Karsch's description of Petrooicus in a literature review . The name is considered an unintentional misspelling.
  • Protophthalmus Lawrence , 1969: The South African arachnologist Reginald Frederick Lawrence placed this new species in the new genus Protophthalmus when he first described Opistophthalmus holmi in 1969 because of several poorly developed or missing physical characteristics . He called the genus "more primitive" than Opistophthalmus , which in turn was "more primitive" than Scorpio and Pandinus . The description of a new genus seemed justified at the time because of the great differences between Opistophthalmus holmi and the other species of the genus Opistophthalmus . 1972 described Gerald Newlands with Opistophthalmus concinnus a new species from the Kalahari, which in terms of their physical characteristics as a link between Opistophthalmus Holmi represents and the other species. Since the unique selling points for protophthalmos were missing and no clear distinction between the genera was possible anymore, Newlands declared protophthalmos to be a synonym for opistophthalmos.

species

Opistophthalmus carinatus in a threatening position
Opistophthalmus glabrifrons
Opistophthalmus pugnax
Opistophthalmus wahlbergii

The genus Opistophthalmus currently includes almost 60 species. The American arachnologist Lorenzo Prendini carried out a revision of the genus for his dissertation in 2001 and distinguished 76 species when examining more than 17,000 collection copies, but only published the descriptions of the new species informally. With a view to a planned revision of the genus Opistophthalmus and its publication as a monograph, Prendini named an expected number of 80 and 85 species.

Medical importance

Opistophthalmus glabrifrons in a threatening pose

Opistophthalmus glabrifrons is one of the few scorpions in the Scorpionidae family whose sting can cause serious symptoms of poisoning. However, the poisoning caused by it is not considered life-threatening, and the available antivenome is only effective against the poison of species of the genus Parabuthus . For stings of all types of opistophthalmos , pain therapy is in the foreground in medical care. No other species of the genus Opistophthalmus has been known to have been severely poisoned by humans, and the number ofpoisonings causedby Opistophthalmus glabrifrons is very low. All fatal scorpion poisoning in southern Africa iscausedby Parabuthus granulatus or Parabuthus transvaalicus .

In mammals and birds , the intravenously injected scorpion toxin from Opistophthalmus glabrifrons causes increased salivation, tremors , paralysis and, with sufficiently high doses, death as a result of peripheral respiratory paralysis . With the exception of salivation, the symptoms are similar to poisoning by Parabuthus , but the amount of poison required to produce these symptoms is higher in Opistophthalmus glabrifrons than in the Parabuthus species. In the case of intracutaneous injection , edema , bleeding , inflammation and finally necrosis occur in the area of ​​the injection site . These local symptoms are absent when the Parabuthus venom is injected .

toxicology

The scorpion venom are mixtures of many proteins , as in different ways toxins are effective. Since the species of Opistophthalmus do not pose a significant threat to humans in comparison to the species of Parabuthus occurring in the same area, they have only been the subject of toxicology research to a limited extent in the past .

Two proteins with the names opicalcin-1 and opicalcin-2 (or P60252 and P60253) were isolated from the poison of Opistophthalmus carinatus . Both toxins bind to the ryanodine receptor RYR1, which plays a role in triggering muscle contractions, and strongly influence its behavior. In doing so, they bind to a different location than ryanodine .

pharmacology

The poison of Opistophthalmus carinatus contains two pore-forming toxins , opistoporin-1 and opistoporin-2, which only differ in one amino acid and belong to the α-helical antimicrobial peptides . The two opistoporins show a stronger antimicrobial effect against gram-negative bacteria than against gram-positive bacteria. In addition, they have an antifungal effect .

From the venom of Opistophthalmus glabrifrons was cysteine peptide Opisin isolated. In laboratory tests, even in low doses, opisin shows a strong antimicrobial effect against gram-positive bacteria, including methicillin-resistant Staphylococcus aureus and vancomycin-resistant enterococci . The antibiotic effect against gram-negative bacteria and the human pathogenic fungus Candida tropicalis was significantly lower. It is currently being investigated whether opisin can serve as a template for the development of antibiotics for the treatment of infections with multi-resistant germs.

literature

  • EB Eastwood: Notes on the scorpion fauna of the Cape. Part 1. Description of neotypes of Opisthophthalmus capensis (Herbst) and remarks on the O. capensis and O. granifrons Pocock species-groups (Arachnida, Scorpionida, Scorpionidae). In: Annals of the South African Museum 1977, Volume 72, Article 11, pp. 211-226, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dannalsofsouth72111977sout~MDZ%3D%0A~SZ%3D~doppelseiten%3D~LT%3D~PUR%3D .
  • EB Eastwood: Notes on the scorpion fauna of the Cape. Part 3. Some observations on the distribution and biology of scorpions on Table Mountain. In: Annals of the South African Museum 1978, Volume 74, Article 10, pp. 229-248, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dannalsofsouthafr74sout~MDZ%3D%0A~SZ%3Dn309~ double-sided%3Dja~LT%3D~PUR%3D .
  • EB Eastwood: Notes on the scorpion fauna of the Cape. Part 4. The burrowing activities of some scorpionids and buthids (Arachnida, Scorpionida). In: Annals of the South African Museum 1978, Volume 74, Article 11, pp. 249-255, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dannalsofsouthafr74sout~MDZ%3D%0A~SZ%3Dn337~ double-sided%3Dja~LT%3D~PUR%3D .
  • Victor Fet, Gary A. Polis, and W. David Sissom: Life in sandy deserts: the scorpion model. In: Journal of Arid Environments 1998, Volume 39, No. 4, pp. 609-622, doi : 10.1006 / jare.1997.0386 .
  • Oscar F. Francke: Conspectus genericus scorpionorum 1758-1982 (Arachnida: Scorpiones). In: Occasional Papers of the Museum, Texas Tech University 1985, No. 98, pp. 1-32, Online PDF
  • Reginald Frederick Lawrence: A new genus of psammophile scorpion and new species of Opistophthalmus from the Namib Desert. In: Scientific Papers of the Namib Desert Research Station 1969, Volume 48, pp. 105-116, Online PDF .
  • Gerald Newlands: Notes on psammophilic scorpions and a description of a new species (Arachnida: Scorpionides). In: Annals of the Transvaal Museum 1972, Volume 27, No. 12, pp. 241-255 and Plate 22, Online PDF .
  • Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae (Chelicerata: Scorpiones) with a discussion on phylogenetic methods. In: Invertebrate Systematics 2003, Volume 17, No. 2, pp. 185-259, doi : 10.1071 / IS02016 .
  • Lorenzo Prendini: Scorpion diversity and distribution in southern Africa: Pattern and process. In: Bernhard A. Huber, Bradley J. Sinclair and Karl-Heinz Lampe (eds.): African Biodiversity. Molecules, Organisms, Ecosystems. Springer, New York 2005, ISBN 978-0-387-24320-7 , pp. 25-68.

Individual evidence

  1. ↑ a b c d e f Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 223.
  2. ↑ Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 226.
  3. ↑ Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 212.
  4. ↑ a b c Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 214.
  5. ^ A b Anne J. Alexander: On the stridulation of scorpions. In: Behavior 1958, Volume 12, No. 4, pp. 339-352, doi : 10.1163 / 156853958X00028 .
  6. ^ Anne J. Alexander and DW Ewer: A chemo-receptor in the scorpion Opisthophthalmus. In: South African Journal of Science 1957, Volume 53, No. 16, pp. 421-422, ZDB -ID 421752-4 .
  7. ↑ Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 217.
  8. ^ A b Reginald Frederick Lawrence: A new genus of psammophile scorpion and new species of Opistophthalmus from the Namib Desert. Pp. 105-106.
  9. ^ Reginald Frederick Lawrence: A new genus of psammophile scorpion and new species of Opistophthalmus from the Namib Desert. P. 110.
  10. ^ Victor Fet, Gary A. Polis and W. David Sissom: Life in sandy deserts, p. 612.
  11. ^ A b Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 44.
  12. ^ EB Eastwood: Notes on the scorpion fauna of the Cape. Part 4, p. 252.
  13. ↑ Ansie S. Dippenaar-Schoeman, Annette van den Berg and Lorenzo Prendini: Spiders and scorpions (Arachnida: Araneae, Scorpiones) of the Nylsvley Nature Reserve, South Africa. In: Koedoe 2009, Volume 51, No. 1, pp. 1-9, online PDF .
  14. ↑ Gerald Newlands: Notes on psammophilic scorpions and a description of a new species, p. 249.
  15. ↑ Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 29.
  16. ↑ Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 35.
  17. ↑ Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 37.
  18. ↑ Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 42.
  19. ↑ a b c d Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 43.
  20. ↑ Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 34.
  21. ^ Victor Fet, Gary A. Polis and W. David Sissom: Life in sandy deserts, p. 616.
  22. ↑ Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 45.
  23. ^ A b Lorenzo Prendini: Scorpion diversity and distribution in southern Africa, p. 46.
  24. ↑ a b c d Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 227.
  25. ^ A b c d E. B. Eastwood: Notes on the scorpion fauna of the Cape. Part 3, pp. 241-242.
  26. ^ EB Eastwood: Notes on the scorpion fauna of the Cape. Part 4, pp. 250-251.
  27. ↑ Gerald Newlands: Notes on psammophilic scorpions and a description of a new species, p. 247.
  28. ↑ a b c Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 187.
  29. ^ EB Eastwood: Notes on the scorpion fauna of the Cape. Part 3, pp. 236-237.
  30. ↑ Bruno H. Lamoral: The Scorpions of Namibia (Arachnida: Scorpionida). In: Annals of the Natal Museum 1979, Volume 23, No. 3, pp. 498–783, here p. 707 download links .
  31. ↑ Wolfgang Bücherl and Eleanor E. Buckley (eds.): Venomous Animals and their Venoms, vol. 3. Venomous invertebrates. Academic Press, New York 1971, p. 334, ISBN 978-0-12-138903-1 .
  32. ^ Anne J. Alexander: The courtship and mating of the scorpion Opisthophthalmus latimanus Koch. In: Proceedings of the Zoological Society of London 1957, Volume 128, No. 4, pp. 529-544, doi : 10.1111 / j.1096-3642.1957.tb00274.x .
  33. ^ EB Eastwood: Notes on the scorpion fauna of the Cape. Part 3, pp. 242-243.
  34. ↑ Bruno H. Lamoral: Predation on terrestrial molluscs by scorpions in the Kalahari Desert. In: Annals of the Natal Museum 1971, Volume 21, No. 1, pp. 17-20, online PDF 150 kB.
  35. ↑ Bruno H. Lamoral: Unusual price of some African Scorpions. In: Bulletin of the British Arachnological Society 1971, Volume 2, No. 2, P. 13, Online PDF 200 kB.
  36. ^ EB Eastwood: Notes on the scorpion fauna of the Cape. Part 3, p. 243.
  37. ↑ JL de Vries et al .: Extension of the diet of an extreme foraging specialist, the aardwolf (Proteles cristata). In: African Zoology 2011, Volume 46, No. 1, pp. 194–196, Online PDF 219 kB.
  38. ↑ J. du P. Bothma: Food habits of some Carnivora (Mammalia) from southern Africa. In: Annals of the Transvaal Museum 1971, Volume 27, No. 2, pp. 15–26, online PDF 510 kB.
  39. ^ David W. Macdonald: Genus Suricata. Meerkat. In: Jonathan Kingdon and Michael Hoffmann (eds.): Mammals of Africa. Volume V: Carnivores, Pangolins, Equids and Rhinoceroses. London: Bloomsbury 2013, ISBN 978-1-4081-2255-6 , pp. 346–352, here p. 349.
  40. ↑ CM Begg et al .: Sexual and seasonal variation in the diet and foraging behavior of a sexually dimorphic carnivore, the honey badger (Mellivora capensis). In: Journal of Zoology 2003, Volume 260, No. 3, 301-317, doi : 10.1017 / S0952836903003789 .
  41. ↑ Anton Kolb: Food and food intake in bats. In: Zeitschrift für Mammaliankunde 1958, Volume 23, pp. 84-95.
  42. ^ Paul A. Gray, M. Brock Fenton and Victor Van Cakenberghe: Nycteris thebaica. In: Mammalian Species 1999, No. 612, pp. 1–8, Online PDF ( Memento of the original from March 4, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. 1.0 MB. @1@ 2Template: Webachiv / IABot / www.science.smith.edu
  43. ^ CJ Vernon: An analysis of owl pellets collected in southern Africa. In: Ostrich 1972, Volume 43, No. 2, pp. 109-124, doi : 10.1080 / 00306525.1972.9632586 .
  44. ↑ Laura Baldo et al .: Wolbachia are present in southern african scorpions and cluster with supergroup F. In: Current Microbiology 2007, Volume 55, pp. 367-373, doi : 10.1007 / s00284-007-9009-4 .
  45. ↑ Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 229.
  46. ↑ Michael E. Soleglad and Victor Fet: High-level systematics and phylogeny of the extant scorpions (Scorpiones: Orthosterni). In: Euscorpius 2003, No. 11, p. 1 Online PDF ( Memento of the original from March 9, 2016 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. . @1@ 2Template: Webachiv / IABot / www.science.marshall.edu
  47. ↑ Michael E. Soleglad, Victor Fet and František Kovařík: The systematic position of the scorpion genera Heteroscorpion Birula, 1903 and Urodacus Peters, 1861 (Scorpiones: Scorpionoidea). In: Euscorpius 2005, No. 20, pp. 1–38, online PDF .
  48. ^ Victor Fet and Michael E. Soleglad: Contributions to scorpion systematics. I. On recent changes in high-level taxonomy. In: Euscorpius 2005, No. 31, pp. 1–13, online PDF .
  49. ↑ for example Carlos E. Santibáñez-López, Ricardo Kriebel and Prashant P. Sharma: eadem figura manet: Measuring morphological convergence in diplocentrid scorpions (Arachnida: Scorpiones: Diplocentridae) under a multilocus phylogenetic framework. In: Invertebrate Systematics 2017, Volume 31, No. 3, pp. 233–248, Online PDF 1.8 MB.
  50. ↑ a b c Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 210.
  51. ↑ Lorenzo Prendini: Phylogeny and classification of the superfamily Scorpionoidea Latreille 1802 (Chelicerata, Scorpiones): an exemplar approach. In: Cladistics 2000, Volume 16, No. 1, pp. 1-78, here pp. 34-35, doi : 10.1111 / j.1096-0031.2000.tb00348.x .
  52. ↑ Lorenzo Prendini and Ward C. Wheeler: Scorpion higher phylogeny and classification, taxonomic anarchy, and standards for peer review in online publishing. In: Cladistics 2005, Volume 21, No. 5, pp. 446-494, Online PDF 1.8 MB.
  53. ^ John Hewitt: Facts and theories on the distribution of scorpions in South Africa. In: Transactions of the Royal Society of South Africa 1924, Vol. 12, No. 1, pp. 249-276, doi : 10.1080 / 00359192409519304 .
  54. ↑ Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 206.
  55. ↑ Prashant P. Sharma, Rosa Fernández, Lauren A. Esposito, Edmundo González-Santillán, Lionel Monod (2015): Phylogenomic resolution of scorpions reveals multilevel discordance with morphological phylogenetic signal. Proceedings of the Royal Society B (Biological Sciences) 282 (1804): article 20142953. doi: 10.1098 / rspb.2014.2953
  56. ↑ a b c d Carl Ludwig Koch: Overview of the arachnid system. CH Zeh'sche Buchhandlung, Nuremberg 1837, pp. 36–37 and Plate VI, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dbersichtdesara1518371850koch~MDZ%3D%0A~SZ%3Dn154~doppelseiten%3Dja~LT%3D~PUR%3D .
  57. ^ EB Eastwood: Notes on the scorpion fauna of the Cape. Part 1, pp. 211-212.
  58. ^ EB Eastwood: Notes on the scorpion fauna of the Cape. Part 1, pp. 212-216.
  59. ↑ Gérard Dupré: Dictionary of scientific scorpion names. In: Arachnides. Bulletin de Terrariophilie et de Recherche 2016, Supplément au n ° 78, Online PDF .
  60. ↑ Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, p. 251.
  61. ^ Oscar F. Francke: Conspectus genericus scorpionorum 1758-1982, p. 5.
  62. ↑ a b Victor Fet: Scorpionidae. In: Victor Fet et al .: Catalog of the scorpions of the world (1758-1998). The New York Entomological Society, New York 2000, download links , pp. 427-486, here p. 449.
  63. ^ Tord Tamerlan Teodor Thorell: On the classification of Scorpions. In: Annals and Magazine of Natural History 1876, Series 4, Volume 17, No. 97, pp. 1–15, digitized versionhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dannalsmagazineof4171876lond~MDZ%3D%0A~SZ%3Dn15~ double-sided%3Dja~LT%3D~PUR%3D , here p. 13.
  64. ^ Karl Kraepelin: Revision of the scorpions. II. Scorpionidae and Bothriuridae. In: Yearbook of the Hamburg Scientific Institutions 1893, Volume 11 (published 1894), pp. 26 and 77, digitized version http: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dmitteilungenausd1112189394hamb~MDZ%3D%0A~SZ%3D~doppelseiten%3D~LT%3D~PUR%3D(entire volume).
  65. ^ A b Eugène Simon: Etudes arachnologiques. 20 ° mémoire. XXVIII. Arachnides recueillis dans le sud de l'Afrique par le docteur Hans Schinz. In: Annales de la Société Entomologique de France 1888, Volume 6, No. 7, pp. 369–384, here pp. 380–383, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dannalesdelasoci681888soci~MDZ%3D%0A~SZ%3D375~doppelseiten%3Dja~LT%3D~PUR%3D .
  66. ↑ a b c Reginald Innes Pocock: Notes on the classification of Scorpions, followed by some observations upon synonymy, with descriptions of new genera and species. In: Annals and Magazine of Natural History 1893, Series 6, Volume 12, pp. 303-330, here p. 307, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dannalsmagazineof6121893lond~MDZ%3D%0A~SZ%3Dn317~doppelseiten%3Dja~LT%3D~PUR%3D .
  67. ^ Oscar F. Francke: Conspectus genericus scorpionorum 1758-1982, p. 10.
  68. ^ Karl Kraepelin: Scorpiones and Pedipalpi. In: Friedrich Dahl (Ed.): The animal kingdom. A compilation and identification of the recent animal forms. Published by the German Zoological Society. 8. Delivery. Arachnoid. Friedländer and Son, Berlin 1899, pp. 132-133, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dscorpionesundped00krae~MDZ%3D%0A~SZ%3D~doppelseiten%3D~LT%3D~PUR%3D .
  69. ↑ Wilhelm Peters: About a new division of scorpions and about the species of scorpions he collected in Mossambique, from which an extract is given here. In: Monthly reports of the Royal Prussian Academy of Sciences in Berlin 1861, first half, pp. 507–516, here pp. 514–515, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dmonatsberichtede18611knig~MDZ%3D%0A~SZ%3Dn544~doppelseiten%3Dja~LT%3D~PUR%3D .
  70. ^ Oscar F. Francke: Conspectus genericus scorpionorum 1758-1982, pp. 3 and 11.
  71. ^ Ferdinand Karsch: Scorpionological contributions. II. In: Communications of the Munich Entomological Association 1879, Volume 3, No. 2, pp. 97-136, digitizedhttp: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dmittheilungendes35187981mn~MDZ%3D%0A~SZ%3Dn119~ double-sided%3Dja~LT%3D~PUR%3D .
  72. ^ Anton Ausserer: 8th Arachnida. In: Zoological annual report for 1879, pp. 430–470, here p. 467, digitized version http: //vorlage_digitalisat.test/1%3D~GB%3D~IA%3Dzoologischerjahr0001staz~MDZ%3D%0A~SZ%3Dn446~doppelseiten%3Dja~LT%3D~PUR%3D.
  73. ^ Oscar F. Francke: Conspectus genericus scorpionorum 1758-1982, p. 12.
  74. ↑ Gerald Newlands: Notes on psammophilic scorpions and a description of a new species, pp. 243-244.
  75. ↑ Lorenzo Prendini, Timothy M. Crowe and Ward C. Wheeler: Systematics and biogeography of the family Scorpionidae, pp. 227 and 252.
  76. ^ Lorenzo Prendini: Systematics. Evolution and biogeography of the Southern African burrowing scorpions. Opistophthalmus CL Koch (Scorpiones, Scorpionidae). PhD Thesis, University of Cape Town 2001, p. 587, Online PDF 34.9 MB.
  77. ^ A b Nils J. Bergman: Opisthophthalmus glabrifrons scorpion envenomation. In: South African Medicine Journal 1996, Volume 86, No. 8, pp. 981-982, Online PDF (whole section “Letters”, 5 MB).
  78. ^ Nils J. Bergman: Scorpion sting in Zimbabwe. In: South African Medicine Journal 1997, Volume 87, No. 2, pp. 163-167, Online PDF .
  79. ^ E. Grasset, A. Schaafsma and JA Hodgson: Studies on the venom of South African scorpions (Parabuthus, Hadogenes, Opistophthalmus), and the preparation of a specific antiscorpion serum. In: Transactions of the Royal Society of Tropical Medicine and Hygiene 1946, Volume 39, No. 5, pp. 397-421, doi : 10.1016 / 0035-9203 (46) 90017-X .
  80. ↑ Data sheets for opicalcin-1 and for [1] at UniProt , accessed on September 26, 2017.
  81. ↑ Leentje Moerman et al .: Antibacterial and antifungal properties of α-helical, cationic peptides in the venom of scorpions from southern Africa. In: European Journal of Biochemistry 2002, Volume 269, No. 19, pp. 4799-4810, doi : 10.1046 / j.1432-1033.2002.03177.x .
  82. ↑ Aorigele Bao et al .: A novel cysteine-free venom peptide with strong antimicrobial activity against antibiotics-resistant pathogens from the scorpion Opistophthalmus glabrifrons. In: Journal of Peptide Science 2015, Volume 21, No. 10, pp. 758-764, doi : 10.1002 / psc.2801 .

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