Xysticus

Source: Wikipedia, the free encyclopedia.

Ground crab spiders
Temporal range: Palaeogene–present
Xysticus sp.
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Arthropoda
Subphylum: Chelicerata
Class: Arachnida
Order: Araneae
Infraorder: Araneomorphae
Family: Thomisidae
Genus: Xysticus
C. L. Koch, 1835
Species

See text

Female Xysticus sp. with egg sac

Xysticus is a genus of ground

Araneae, family Thomisidae. The genus name is derived from the Ancient Greek
root xyst, meaning "scraped, scraper".

Description

Xysticus and Coriarachne are dark brown or reddish-brown crab spiders often encountered on weeds or trees. While similar to the 'flower spiders', they tend to have shorter, sturdier legs. Many, but not all, species have abdomens more patterned than most Thomisus species, rather like some of the Synema species. Some however, that are more terrestrial, resemble earth in colour and texture.

A ground crab spider with earthy coloration

Most species of the genus Xysticus are small to medium sized spiders. They show a sexual dimorphism in size. Females of typical species reach a maximum of 10 millimetres (0.39 in) of body length, while their males are about 3–5 millimetres (0.12–0.20 in) long, about half the size of the females.

The basic colour of these species is usually brown, beige or gray. The

prosoma is sometimes slightly smaller than the opisthosoma. In many species the front body shows in the middle a broad, pale longitudinal band. The opisthosoma
is clearly flattened in most species and shows a median broad and dark leaf marking.

The species are often very similar to each other, and in most cases can be distinguished only by a microscopic examination of the reproductive organs.

Behaviour

The spiders of the genus Xysticus do not build webs; like most Thomisidae they are ambush hunters and prefer to hunt near the ground (hence the common name "ground crab spiders"). They move slowly, and commonly hunt by stationing themselves in a high-traffic area and grabbing whatever arthropod passes close enough. Also like most other Thomisidae, they seize prey with their enlarged anterior two pairs of legs and kill it by a venomous bite.

Species

As of December 2022 it contains 293 species, found worldwide:[1]

Gallery

  • Xysticus audax
    Xysticus audax
  • Xysticus kochi, female
    Xysticus kochi, female
  • Xysticus cristatus
    Xysticus cristatus
  • Xysticus bilimbatus
    Xysticus bilimbatus
  • Xysticus lanio
    Xysticus lanio
  • Xysticus luctator
    Xysticus luctator
  • Xysticus ninniii
    Xysticus ninniii
  • Xysticus ulmi
    Xysticus ulmi

References

  • Norman I. Platnick - Thomisidae
  • J. H. Redner and C. D. Dondale - A New Species of The Spider Genus Xysticus (Araneae: Thomisidae) From Arizona - PsycheVolume 72 (1965), Issue 4, Pages 291–294
  • H. Demir, O. Seyyar, and M. Aktaş - A Poorly Known Species of the Spider Genus Xysticus C. L. Koch (Araneae, Thomisidae) in Turkey - Arch. Biol. Sci., Belgrade, 60 (4), 17P-18P, 2008

External links