Sicarius is a genus of recluse spiders that are 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. They live in deserts and arid regions of the Neotropics, and females use a mixture of sand and silk when producing egg sacs. The genus name is Latin for assassin.
Distribution Most species in this genus are found in South America, with one species, Sicarius rugosus occurring in Central America, north to Guatemala.
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 genus. They lack the characteristic violin-shaped marking of the more well-known members of its family Sicariidae, the recluse spiders.
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 that contains sphingomyelinase D, an enzyme in the sphingomyelin phosphodiesterase family. It is somewhat unique to them, otherwise only found in a few pathogenic bacteria. The venom causes bleeding 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 and Sicarius ornatus, and that its bite can cause serious damage in humans.
Taxonomy This genus was erected by Charles Athanase Walckenaer in 1847 with the single species, S. thomisoides. In 2017, the number of species placed in the genus decreased after a phylogenetic study showed that the South African species formerly included here were actually distinct, instead belonging to the genus Hexophthalma.
It is one of only three genera in its family, and is placed in the same subfamily as Hexophthalma:
Species , this genus includes 21 species:
Sicarius andinus Magalhaes, Brescovit & Santos, 2017 – Peru Sicarius boliviensis Magalhaes, Brescovit & Santos, 2017 – Bolivia, Peru, Brazil, Paraguay Sicarius cariri Magalhaes, Brescovit & Santos, 2013 – Brazil Sicarius crustosus (Nicolet, 1849) – Chile Sicarius diadorim Magalhaes, Brescovit & Santos, 2013 – Brazil Sicarius fumosus (Nicolet, 1849) – Chile Sicarius gracilis (Keyserling, 1880) – Ecuador, Peru Sicarius jequitinhonha Magalhaes, Brescovit & Santos, 2017 – Brazil Sicarius lanuginosus (Nicolet, 1849) – Chile Sicarius levii Magalhaes, Brescovit & Santos, 2017 – Chile, Argentina Sicarius mapuche Magalhaes, Brescovit & Santos, 2017 – Argentina Sicarius ornatus Magalhaes, Brescovit & Santos, 2013 – Brazil Sicarius peruensis (Keyserling, 1880) – Peru Sicarius rugosus (F. O. Pickard-Cambridge, 1899) – Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica Sicarius rupestris (Holmberg, 1881) – Argentina Sicarius saci Magalhaes, Brescovit & Santos, 2017 – Brazil Sicarius thomisoides Walckenaer, 1847 – Chile (type species) Sicarius tropicus (Mello-Leitão, 1936) – Brazil Sicarius utriformis (Butler, 1877) – Galapagos Sicarius vallenato Cala-Riquelme, Gutiérrez-Estrada, Flórez-Daza & Agnarsson, 2017 – Colombia Sicarius yurensis 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
Arachnology Home Pages: Loxosceles: Recluse spiders Biodiversity Explorer: Family Sicariidae (photos of Sicarius and Loxosceles) World Spider Catalog. Platnick, N. I. 2003. Vetter, R. 2003. "Causes of Necrotic Wounds other than Brown Recluse Spider Bites". Vetter, R. 2003. "Myth of the Brown Recluse: Fact, Fear, and Loathing".