Crab spider

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

From Wikipedia, the free encyclopedia

Jump to: navigation, search

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 backward.

Crab spiders do not build webs to trap prey, but are hunters and ambushers. Some species sit on or among flowers, bark, fruit or leaves where they grab visiting insects. Individuals of some species, such as Misumena vatia, are able to change color between white and yellow to match the flower on which they're sitting. 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. However, spiders of an unrelated genus, Sicarius, which are sometimes referred to as "crab spiders", are close cousins to the recluse spiders, and are highly venomous.

The unrelated species Gasteracantha cancriformis is commonly called the "crab spider."

[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

A crab spider on flower, April 2009	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 a flower	A crab spider on a flower with mites	A crab spider (Diaea evanida) paralysing a moth
A crab spider of Galicia	Galicia