Crab spider

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Crab spiders
Ozyptila praticola
Scientific classification
Kingdom: Animalia Phylum: Arthropoda Class: Arachnida Order: Araneae Superfamily: Thomisoidea Family: Thomisidae Sundevall, 1833
Diversity
170 genera, > 2,000 species
Genera
Amyciaea Aphantochilus Coriarachne Diaea Heriaeus Misumena Misumenoides Misumenops Ozyptila Pistius Rejanellus Runcinia Synema Thomisus Tmarus Xysticus many others

A crab spider (Xysticus sp.) paralysing its prey

Crab spiders make up the Thomisidae family of the Araneae order. They are called crab spiders because they resemble crabs, with two front pairs of legs angled outward and bodies that are flattened and often angular. Also, like crabs, Thomisidae can move sideways or backwards. They are very maneuverable in tight places.

Crab spiders do not build webs to trap prey. They are hunters and ambushers. Some species sit on or among flowers, bark, fruit or leaves where they grab visiting insects. Misumena vatia is one of these. It can change its color between white and yellow to match the flower it sits on. Other species, with their flattened bodies, hunt in the crevices of tree trunks or under loose bark. Members of the genus Xysticus hunt in the leaf litter on the ground. In each case, crab spiders use their powerful front legs to grab and hold onto prey while paralyzing it with a venomous bite.

The spider family Aphantochilidae was incorporated into the Thomisidae in the late 1980s. Aphantochilus species mimic Cephalotes ants, on which they prey.

The spiders of Thomisidae are not known to be harmful to humans. Spiders of an unrelated genus, Sicarius, also resemble crabs (and are sometimes referred to as "crab spiders"). Sicarius spiders, close cousins to the recluse spiders, are highly venomous.

[edit] Systematics

Main article: List of Thomisidae genera

The following subfamilies are recognized:

• Aphantochilinae (3 genera)
• Bominae Ono, 1984 (9 genera)
• Dietinae (32 genera)
• Stephanopinae (35 genera)
• Stiphropodinae (3 genera)
• Strophiinae (8 genera)
• Thomisinae (67 genera)
• incertae sedis

• Ansiea Lehtinen, 2005
• Carcinarachne Schmidt, 1956
• Cozyptila Lehtinen & Marusik, 2005
• Ebelingia Lehtinen, 2005
• Facundia Petrunkevitch, 1942 † (fossil)
• Fiducia Petrunkevitch, 1942 † (fossil)
• Henriksenia Lehtinen, 2005
• Hexommulocymus Caporiacco, 1955
• Ledouxia Lehtinen, 2005
• Mastira Thorell, 1891
• Megapyge Caporiacco, 1947
• Modysticus Gertsch, 1953
• Rejanellus Lise, 2005
• Syphax Koch & Berendt, 1854 † (fossil)
• Tarrocanus Simon, 1895
• Taypaliito Barrion & Litsinger, 1995

There are 9 genera, containing 130 species of crab spiders in North America.

[edit] Gallery

Diaea dorsata	Misumenoides formocipes	Misumena vatia with wasp	Ozyptila atomaria
Runcinia acuminata	Misumena vatia	A crab spider is hiding in Iris	A crab spider in Iris
A crab spider on flower

[edit] See also

• List of Thomisidae species
• Spider families

[edit] References

• Biolib family Thomisidae
• Lise, A.A. (2005). Rejanellus, a new genus of Thomisidae (Araneae, Stephanopinae). Iheringia, Sér. Zool. 95(2):151-164. PDF

[edit] External links

Wikispecies has information related to:

Thomisidae

Wikimedia Commons has media related to:

Thomisidae

• Crab Spider Misumenoides formocipes diagnostic photos
• Crab Spider Xysticus sp. photos and information
• Tmarus angulatus guarding her eggs
• Picture of Amyciaea albomaculata
• Pictures and text of crab spiders
• Photos of American Crab Spiders
• Photos and Info on Australian Crab Spiders
• Kentucky Crab Spiders Photos and Information
• Picture of Stephanopis championi
• Pictures of crab spiders (free for noncommercial use)