''Sicarius'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

recluse spider The recluse spiders (''Loxosceles'' (), also known as brown spiders, fiddle-backs, violin spiders, and reapers, is a genus of spiders that was first described by R. T. Lowe in 1832. They are venomous spiders known for their bite, which sometimes ...

s that is potentially medically significant to humans. It is one of three genera in its family, all venomous spiders known for a bite that can induce

loxoscelism Loxoscelism () is a condition occasionally produced by the bite of the recluse spiders (genus ''Loxosceles''). The area becomes dusky and a shallow open sore forms as the skin around the bite dies (necrosis). It is the only proven type of necro ...

. They live in deserts and arid regions of the Southern Hemisphere, and females use a mixture of sand and silk when producing egg sacs. The name is Latin for assassin.

Description

''Sicarius'' spiders can grow up to long, and have six eyes arranged into three groups of two (known as "dyads"). Physically, they resemble crab spiders and members of the ''

Homalonychus ''Homalonychus'' is a genus of araneomorph spiders, and is the only genus in the family Homalonychidae. It was first described by George Marx in 1891. it contains only two species: '' H. selenopoides'' and '' H. theologus''. They are found in th ...

'' genus. They lack the characteristic violin-shaped marking of the more well-known members of its family,

Sicariidae Sicariidae is a family of six-eyed venomous spiders known for their potentially necrotic bites. The family consists of three genera and about 160 species. Well known spiders in this family include the brown recluse spider and the six-eyed sand ...

the

recluse spiders The recluse spiders (''Loxosceles'' (), also known as brown spiders, fiddle-backs, violin spiders, and reapers, is a genus of spiders that was first described by R. T. Lowe in 1832. They are venomous spiders known for their bite, which sometimes ...

. They can live for a very long time without food or water. Some can live for up to fifteen years, making them among the longest-lived spiders, behind the trap-door spiders and tarantulas, many known to live for twenty to thirty years. The oldest recorded spider is Number 16, a trap-door spider killed by a parasitic wasp at forty-three years old.

Venom components and effects

Like all recluse spiders, these produce a dermonecrotic

venom Venom or zootoxin is a type of toxin produced by an animal that is actively delivered through a wound by means of a bite, sting, or similar action. The toxin is delivered through a specially evolved ''venom apparatus'', such as fangs or a ...

that contains

sphingomyelinase D Sphingomyelin phosphodiesterase D (EC 3.1.4.41, sphingomyelinase D) is an enzyme of the sphingomyelin phosphodiesterase family with systematic name sphingomyelin ceramide-phosphohydrolase. These enzymes catalyse the hydrolysis of sphingomyelin, re ...

, an

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrate (chemistry), substrates, and the enzyme converts the substrates into different molecule ...

in the

sphingomyelin phosphodiesterase Sphingomyelin phosphodiesterase (EC 3.1.4.12, also known as neutral sphingomyelinase, sphingomyelinase, or SMase; systematic name sphingomyelin cholinephosphohydrolase) is a hydrolase enzyme that is involved in sphingolipid metabolism reactions. ...

family. It is somewhat unique to them, otherwise only found in a few

pathogenic bacteria Pathogenic bacteria are bacteria that can cause disease. This article focuses on the bacteria that are pathogenic to humans. Most species of bacteria are harmless and are often beneficial but others can cause infectious diseases. The number of th ...

. The venom causes

bleeding Bleeding, hemorrhage, haemorrhage or blood loss, is blood escaping from the circulatory system from damaged blood vessels. Bleeding can occur internally, or externally either through a natural opening such as the mouth, nose, ear, urethra, vag ...

and damage to many organs of the body, though only '' S. ornatus'' and a few others have been proven to be extremely toxic on the order of '' Hexophtalma hahni'' or several other African sand spiders. It has also recently been proven that Sicarius thomisoides contains active sphingomyelinase D, very similar to that of Loxosceles laeta The Chilean recluse spider, ''Loxosceles laeta'', is a highly venomous spider of the family Sicariidae. In Spanish, it (and other South American recluse spiders) is known as ', or "corner spider"; in Brazilian Portuguese, as ' or "brown spider" ...
and Sicarius ornatus, and that its bite can cause serious damage in humans.

Taxonomy

This genus was erected by

Charles Athanase Walckenaer Baron Charles Athanase Walckenaer (25 December 1771 – 28 April 1852) was a French civil servant and scientist. Biography Walckenaer was born in Paris and studied at the universities of Oxford and Glasgow. In 1793 he was appointed head of t ...

in 1847 with the single species, '' S. thomisoides''. In 2017, the number of species decreased after a phylogenetic study showed that the

South Africa South Africa, officially the Republic of South Africa (RSA), is the southernmost country in Africa. It is bounded to the south by of coastline that stretch along the South Atlantic and Indian Oceans; to the north by the neighbouring count ...

n species formerly included here were actually distinct, instead belonging to the genus ''

Hexophthalma ''Hexophthalma'' is a genus of spiders in the family Sicariidae. Although the genus was originally erected in 1878 (then with the name ''Hexomma''), it was merged into the genus '' Sicarius'' in the 1890s, and remained unused until revived in 2 ...

''. It is one of only three genera in its family, and is placed in the same subfamily as ''Hexophthalma'':

Species

it contains twenty-one species, found in South America, Costa Rica,

El Salvador El Salvador (; , meaning " The Saviour"), officially the Republic of El Salvador ( es, República de El Salvador), is a country in Central America. It is bordered on the northeast by Honduras, on the northwest by Guatemala, and on the south by ...

, and

Nicaragua Nicaragua (; ), officially the Republic of Nicaragua (), is the largest Sovereign state, country in Central America, bordered by Honduras to the north, the Caribbean Sea, Caribbean to the east, Costa Rica to the south, and the Pacific Ocean to ...

: *''

Sicarius andinus The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' Magalhães, Brescovit & Santos, 2017 –

Peru , image_flag = Flag of Peru.svg , image_coat = Escudo nacional del Perú.svg , other_symbol = Great Seal of the State , other_symbol_type = Seal (emblem), National seal , national_motto = "Fi ...

*''

Sicarius boliviensis The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' Magalhães, Brescovit & Santos, 2017 –

Bolivia , image_flag = Bandera de Bolivia (Estado).svg , flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center , flag_alt2 = 7 × 7 square p ...

, Peru,

Brazil Brazil ( pt, Brasil; ), officially the Federative Republic of Brazil (Portuguese: ), is the largest country in both South America and Latin America. At and with over 217 million people, Brazil is the world's fifth-largest country by area ...

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

*''

Sicarius cariri The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' Magalhães, Brescovit & Santos, 2013 – Brazil *''

Sicarius crustosus The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' (Nicolet, 1849) –

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the eas ...

*''

Sicarius diadorim The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' Magalhães, Brescovit & Santos, 2013 – Brazil *'' Sicarius fumosus'' (Nicolet, 1849) – Chile *''

Sicarius gracilis The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' (

Keyserling Keyserling is the surname of several members of the noble House of Keyserlingk: * Alexander Keyserling (1815–1891), Russian geologist, paleontologist, botanist and zoologist * Eugen von Keyserling (1833–1889), German arachnologist * Hermann ...

, 1880) –

Ecuador Ecuador ( ; ; Quechuan languages, Quechua: ''Ikwayur''; Shuar language, Shuar: ''Ecuador'' or ''Ekuatur''), officially the Republic of Ecuador ( es, República del Ecuador, which literally translates as "Republic of the Equator"; Quechuan ...

, Peru *'' Sicarius jequitinhonha'' Magalhães, Brescovit & Santos, 2017 – Brazil *''

Sicarius lanuginosus The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' (Nicolet, 1849) – Chile *''

Sicarius levii The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' Magalhães, Brescovit & Santos, 2017 – Chile,

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, t ...

*'' Sicarius mapuche'' Magalhães, Brescovit & Santos, 2017 – Argentina *'' Sicarius ornatus'' Magalhães, Brescovit & Santos, 2013 – Brazil *''

Sicarius peruensis The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' (Keyserling, 1880) – Peru *'' Sicarius rugosus'' ( F. O. Pickard-Cambridge, 1899) –

, Costa Rica *''

Sicarius rupestris The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' (Holmberg, 1881) – Argentina *'' Sicarius saci'' Magalhães, Brescovit & Santos, 2017 – Brazil *'' Sicarius thomisoides'' Walckenaer, 1847 (

type Type may refer to: Science and technology Computing * Typing, producing text via a keyboard, typewriter, etc. * Data type, collection of values used for computations. * File type * TYPE (DOS command), a command to display contents of a file. * Ty ...

) – Chile *'' Sicarius tropicus'' ( Mello-Leitão, 1936) – Brazil *''

Sicarius utriformis The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' (

Butler A butler is a person who works in a house serving and is a domestic worker in a large household. In great houses, the household is sometimes divided into departments with the butler in charge of the dining room, wine cellar, and pantry. Some al ...

, 1877) – Ecuador (Galapagos) *''

Sicarius vallenato The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' Cala-Riquelme, Gutiérrez-Estrada, Flórez-Daza & Agnarsson, 2017 – Colombia *''

Sicarius yurensis The Sicarii were a self-defense splinter group of Hebrew zealots who opposed the Roman occupation of Judea in the decades preceding the destruction of Jerusalem in 70 CE. Sicarius, sicarii or sicari may also refer to: * Sicarii (1989), a Jewish ...

'' Strand, 1908 – Peru, Chile In synonymy: *''S. deformis'' (Nicolet, 1849) = ''Sicarius fumosus'' (Nicolet, 1849) *''S. irregularis'' (Mello-Leitão, 1940) = ''Sicarius rupestris'' (Holmberg, 1881) *''S. minoratus'' (Nicolet, 1849) = ''Sicarius thomisoides'' Walckenaer, 1847 *''S. nicoleti'' (Keyserling, 1880) = ''Sicarius thomisoides'' Walckenaer, 1847 *''S. patagonicus'' Simon, 1919 = ''Sicarius rupestris'' (Holmberg, 1881) *''S. rubripes'' (Nicolet, 1849) = ''Sicarius thomisoides'' Walckenaer, 1847 *''S. terrosus'' (Nicolet, 1849) = ''Sicarius thomisoides'' Walckenaer, 1847 Transferred to ''Hexophthalma * ''Sicarius albospinosus'' = '' Hexophthalma albospinosa'' (Purcell, 1908) * ''Sicarius damarensis'' = '' Hexophthalma damarensis'' (Lawrence, 1928) * ''Sicarius dolichocephalus'' = '' Hexophthalma dolichocephala'' (Lawrence, 1928) * ''Sicarius hahni'' = '' Hexophthalma hahni'' (Karsch, 1878) (also = ''Sicarius testaceus'') * ''Sicarius spatulatus'' = '' Hexophthalma spatulata'' (Pocock, 1900)

References

External links