Crab-spider
Guides
Bassaniana floridana
Bassaniana floridana is a crab spider species in the family Thomisidae, first described by Nathan Banks in 1896. The species occurs in the United States. As a member of the genus Bassaniana, it belongs to a group of spiders known for their ambush predatory behavior and crab-like leg posture. Specific details about its biology and ecology remain limited in published literature.
Bassaniana utahensis
Utah Crab Spider
Bassaniana utahensis is a crab spider species in the family Thomisidae, commonly known as the Utah Crab Spider. It is native to western North America, occurring in Canada and the United States. As a member of the bark crab spider genus Bassaniana, it is typically associated with trees and woody vegetation where it employs ambush predation. The species was first described by Gertsch in 1932.
Bassaniana versicolor
Multicolored Bark Crab Spider
Bassaniana versicolor is a crab spider in the family Thomisidae, native to North America. Females reach 6.75 mm in length, while males are smaller at 3.8–4.5 mm. The species exhibits color variation with a brown body marked by white spots. It is commonly known as the Multicolored Bark Crab Spider.
Coriarachne
Coriarachne is a genus of crab spiders (Thomisidae) described by Thorell in 1870. The genus currently contains four species distributed across boreal and temperate regions of Europe, Asia, and North America. Many previously described species have been synonymized or transferred to related genera including Bassaniana, Bassaniodes, and Pycnaxis.
Coriarachne brunneipes
Brown-legged Crab Spider
Coriarachne brunneipes is a species of crab spider in the family Thomisidae, commonly known as the Brown-legged Crab Spider. It occurs across the United States and Canada. The species is known for its habitat association with tree bark and documented maternal care behavior.
Diaea
Flower Spiders
Diaea is a genus of crab spiders (family Thomisidae) first described by Thorell in 1869. The genus contains 46 species as of September 2025, most with restricted distributions except for D. livens (United States) and D. dorsata (Palearctic). Adults range 4–7 mm in body length and are strongly associated with vegetation, particularly flowers, where their green, yellow, or white coloration provides camouflage.
Mecaphesa
crab spiders
Mecaphesa is a genus of crab spiders in the family Thomisidae, first described by Eugène Simon in 1900. The genus contains approximately 49 species distributed across North America, Central America, the Caribbean, South America, and Hawaii. Species exhibit cryptic coloration for ambush predation on flowers.
Mecaphesa carletonica
northeastern flower crab spider
Mecaphesa carletonica is a species of crab spider in the family Thomisidae. It is found in the United States and Canada. As a member of the genus Mecaphesa, it belongs to a group of flower-dwelling crab spiders that ambush pollinators. The species was described by Dondale and Redner in 1976.
Mecaphesa celer
swift crab spider
Mecaphesa celer is a crab spider in the family Thomisidae, commonly known as the swift crab spider. It is distributed across much of North and Central America. The species exhibits extreme sexual size dimorphism, with females more than twice the size of males. It is a sit-and-wait predator that hunts on flowers and upper plant parts, and has been studied for its population genetics in fragmented volcanic habitats.
Mecaphesa coloradensis
Colorado Mecaphesa
Mecaphesa coloradensis is a species of crab spider in the family Thomisidae. The species is found in the United States and Mexico. As a member of the genus Mecaphesa, it shares the characteristic ambush-hunting behavior typical of crab spiders, waiting on flowers to capture pollinating insects. The specific epithet 'coloradensis' suggests a connection to Colorado, though the full geographic range extends beyond this state.
Mecaphesa deserti
Mecaphesa deserti is a species of crab spider in the family Thomisidae. It was described by Schick in 1965. The species occurs in arid regions of the southwestern United States and Mexico, consistent with its specific epithet referencing desert habitats. As a member of the genus Mecaphesa, it belongs to a group of spiders characterized by laterigrade leg orientation and ambush predation behavior.
Mecaphesa dubia
Mecaphesa dubia is a species of crab spider in the family Thomisidae. It occurs in the United States and Mexico. As a member of the genus Mecaphesa, it belongs to a group of crab spiders characterized by hairy bodies and cryptic coloration. The species was described by Keyserling in 1880.
Mecaphesa quercina
oak crab spider
Mecaphesa quercina, commonly known as the oak crab spider, is a species of crab spider in the family Thomisidae. The species was described by Schick in 1965. It is known from the United States, though specific details about its biology and ecology remain limited in published sources. As a member of the crab spider family, it likely exhibits the characteristic ambush predation behavior typical of Thomisidae.
Mecaphesa rothi
Mecaphesa rothi is a species of crab spider in the family Thomisidae. It is found in the United States and Mexico. As a member of the genus Mecaphesa, it shares the ambush-hunting strategy characteristic of crab spiders, waiting on flowers to capture pollinating insects. The species was described by Schick in 1965.
Mecaphesa schlingeri
Mecaphesa schlingeri is a species of crab spider in the family Thomisidae, described by Schick in 1965. It is known from the United States, where it has been documented as a predator on the sticky annual plant Madia elegans (tarweed). The species is one of several predators that can navigate the resinous, hooked trichomes of tarweed to feed on trapped insect carrion. Research indicates its presence on tarweed plants increases when dead insects are experimentally added, suggesting it responds to carrion availability.
Mecaphesa sierrensis
Mecaphesa sierrensis is a species of crab spider in the family Thomisidae, first described by Schick in 1965. The genus Mecaphesa comprises small to medium-sized ambush predators that typically hunt on flowers. As a member of this genus, M. sierrensis likely exhibits the cryptic coloration and sit-and-wait predatory strategy characteristic of flower-dwelling thomisids. The species has been recorded from western North America, including British Columbia, Canada and the United States.
Mecaphesa verityi
Mecaphesa verityi is a crab spider in the family Thomisidae, first described by Schick in 1965. The genus Mecaphesa comprises small to medium-sized spiders that ambush prey on flowers. Like other members of this genus, M. verityi likely exhibits cryptic coloration to blend with blossoms where it waits for pollinators. The species is known from the United States, though specific ecological details remain poorly documented in published literature.
Misumena
Flower Crab Spiders
Misumena is a genus of crab spiders in the family Thomisidae, commonly known as flower crab spiders. The genus contains approximately 40 species distributed across the Northern Hemisphere, with the most well-known species being Misumena vatia, the goldenrod crab spider. These spiders are ambush predators that hunt on flowers, where they rely on camouflage to capture pollinating insects. Some species, particularly females of M. vatia, exhibit remarkable color-changing abilities, shifting between white and yellow to match their floral substrate.
Misumena vatia
goldenrod crab spider, flower crab spider, white death spider
Misumena vatia is a crab spider in the family Thomisidae found across the northern hemisphere in North America and Europe. Adult females are ambush predators that hunt on flowers, where they capture pollinating insects using venom and their enlarged front legs. Females possess a remarkable ability to change color between yellow and white to match their floral substrate, a process taking 6–25 days depending on direction. The species exhibits extreme sexual dimorphism: females reach 6–11 mm while males are only 2.5–5 mm and lack color-changing ability. Females are sedentary, occupying single flowers for extended periods, while males actively search for mates following silk draglines.
Misumenoides
whitebanded crab spider
Misumenoides is a genus of crab spiders in the family Thomisidae, established by F. O. Pickard-Cambridge in 1900. The genus contains approximately 35 species distributed primarily in the Americas, with M. formosipes (whitebanded crab spider) being the most thoroughly documented species in North America. These spiders are ambush predators that typically hunt on flowers, using their crab-like front legs to grasp prey. The genus has been recently recorded from Bangladesh, extending its known distribution to South Asia.
Misumenoides formosipes
White-banded Crab Spider
Misumenoides formosipes is a crab spider (family Thomisidae) commonly known as the white-banded crab spider, named for the distinctive white ridge running through the plane of its eyes. The species exhibits pronounced sexual dimorphism, with females significantly larger than males and capable of changing color between white and yellow to match their surroundings, while males maintain a fixed gold coloration with darker front legs. This sit-and-wait predator hunts pollinators on flowers without building webs.
Misumenoides quetzaltocatl
Misumenoides quetzaltocatl is a species of crab spider in the family Thomisidae, described by Jiménez in 1992. The genus Misumenoides comprises flower crab spiders that ambush prey on vegetation. As a Neotropical species known from Mexico, it shares the characteristic crab-like body form and anteriorly directed legs typical of the family. Like congeners, it likely exhibits the sit-and-wait predatory strategy on flowers and foliage.
Misumenops
crab spider
Misumenops is a genus of small crab spiders (family Thomisidae) containing over 50 described species. These spiders are characterized by their flattened bodies and laterally extended legs, typical of ambush predators. Most species occur in the Americas from Canada to Argentina, with some species found on Pacific islands and scattered localities in Asia, Africa, and the Indian subcontinent. Body length ranges from 2–7 mm, with coloration varying from yellow to pale green, often with red or brown patterning. The genus name derives from Misumena (a related crab spider genus) and Greek 'ops' meaning 'looks like'.
Misumessus lappi
Misumessus lappi is a species of crab spider in the family Thomisidae, described by Edwards in 2017. As a member of the genus Misumessus, it belongs to a group of spiders commonly known as flower crab spiders. The species is recorded from the United States. Like other thomisids, it likely employs ambush predation on flowers and vegetation.
Misumessus tamiami
Misumessus tamiami is a species of crab spider in the family Thomisidae, described by Edwards in 2017. It belongs to a genus of spiders known for their ambush predation strategy and crab-like leg positioning. The species name references the Tamiami Trail region of southern Florida, indicating its geographic association with this area.
Modysticus modestus
Modysticus modestus is a species of crab spider in the family Thomisidae. The species was described by Scheffer in 1904 and is known to occur in the United States. As a member of the crab spider family, it likely exhibits the characteristic crab-like posture with legs extended laterally, though specific morphological details for this species are not well documented in available sources.
Ozyptila
Leaflitter Crab Spiders
Ozyptila is a genus of small crab spiders (Thomisidae) established by Eugène Simon in 1864. The genus comprises approximately 103 species distributed across Africa, Europe, North America, and Asia. Members are ground-dwelling spiders with a distinctive pear-shaped, elevated carapace and short, spiny forelegs. They are frequently mistaken for the related genus Xysticus but are generally smaller in body size.
Ozyptila conspurcata
Ozyptila conspurcata is a crab spider in the family Thomisidae, first described by Thorell in 1877. The species is recorded from Canada and the United States, with confirmed observations in Alberta. As a member of the genus Ozyptila, it belongs to a group of small, ground-dwelling crab spiders that ambush prey rather than constructing webs.
Ozyptila pacifica
A small crab spider in the family Thomisidae, first described by Nathan Banks in 1895. The species occurs in western North America from Canada through the United States. Like other members of its genus, it exhibits the characteristic crab-like posture and ambush predation strategy typical of thomisid spiders.
Ozyptila praticola
Eurasian Leaflitter Crab Spider
A small crab spider native to Eurasia that has been introduced to North and South America. Females reach 4 mm and males 3 mm. Adults are active year-round and females guard egg sacs in sheltered microhabitats.
Philodromus keyserlingi
running crab spider
Philodromus keyserlingi is a species of running crab spider in the family Philodromidae. It occurs in the United States and Canada. Like other members of its genus, it is an active hunter that does not build webs to capture prey, instead relying on speed and ambush. The species is part of a diverse genus of crab spiders commonly encountered on vegetation and structures.
Philodromus rufus quartus
Philodromus rufus quartus is a subspecies of running crab spider described by Dondale & Redner in 1968. It belongs to the family Philodromidae, a group of active hunters that do not build webs to capture prey. The subspecies is distributed across a broad Palearctic range including France, Korea, and parts of Russia and Central Asia. As a member of the Philodromus rufus species complex, it exhibits the characteristic laterigrade leg posture and flattened body form typical of bark-dwelling crab spiders.
Spiracme
Spiracme is a genus of crab spiders in the family Thomisidae, erected by Anton Menge in 1876. The genus has undergone extensive taxonomic revision, with species frequently transferred between it and related genera Xysticus and Ozyptila. A 2019 DNA barcoding study by Rainer Breitling helped clarify relationships among these genera. As of January 2026, the genus comprises ten species, including S. striata (the type species) and S. mongolica, which was transferred from Xysticus and represents the first Central European record for the genus.
Spiracme nigromaculatus
Spiracme nigromaculatus is a species of crab spider in the family Thomisidae. It is found in North America. The genus Spiracme is a small group of crab spiders, with species known from both North America and Eurasia.
Synema
Synema is a genus of crab spiders (Thomisidae) with a wide distribution across most parts of the world. The genus includes species with high morphological variability, as demonstrated by integrative studies combining molecular and morphological data. Some species, such as S. globosum, exhibit deep mitochondrial divergence without corresponding nuclear or morphological differentiation, complicating species delimitation. Members of this genus are typically found in leaf-dwelling habitats and exhibit ballooning behavior as juveniles, which contributes to their broad geographic range.
Synema parvulum
Black-banded Crab Spider
Synema parvulum is a crab spider species in the family Thomisidae, first described by Hentz in 1847. It is commonly known as the Black-banded Crab Spider. The species occurs in North America, with confirmed records from the United States and Mexico. It is among the more frequently observed crab spiders in its range, with substantial citizen science documentation.
Synema viridans
Synema viridans is a species of crab spider in the family Thomisidae, found in the United States. As a member of this family, it exhibits the characteristic crab-like posture with laterigrade legs adapted for sideways movement. The genus Synema includes species known for their ambush predation strategy on flowers and vegetation.
Tmarus
Octopus Spiders
Tmarus is a large genus of crab spiders (family Thomisidae) established by Eugène Simon in 1875, with more than 230 described species distributed across all continents except Antarctica. These small to moderate-sized spiders (3.7–7.3 mm body length) are characterized by cryptic bark-like coloration and ambush predatory behavior. The genus exhibits sexual dimorphism, with females typically larger than males.
Tmarus angulatus
Tuberculated Crab Spider
Tmarus angulatus is a species of crab spider in the family Thomisidae, commonly known as the Tuberculated Crab Spider. It is native to North America and belongs to a genus characterized by laterigrade leg orientation that permits sideways movement. As a member of the Thomisidae, it is an ambush predator that does not build webs to capture prey.
Xysticus
Ground Crab Spiders
Xysticus is a large genus of approximately 275–300 species of ground crab spiders in the family Thomisidae. These spiders are ambush predators that do not build webs, instead hunting near the ground by seizing prey with their enlarged anterior legs. The genus exhibits strong sexual dimorphism, with females typically reaching 10 mm in body length while males are roughly half that size. Species identification requires microscopic examination of genitalia due to the morphological similarity among members of the genus.
Xysticus acquiescens
Xysticus acquiescens is a species of ground crab spider in the family Thomisidae, first described by Emerton in 1919. As a member of the genus Xysticus, it is an ambush predator that relies on camouflage and patience rather than web-building to capture prey. The species is known from the Canadian prairies and adjacent regions of the northern United States. Like other Xysticus species, it exhibits typical crab spider morphology with laterally extended legs and a flattened body adapted for hiding in vegetation or ground cover.
Xysticus alboniger
ground crab spider
Xysticus alboniger is a species of ground crab spider in the family Thomisidae. It is found in the United States and Canada, with distribution records from Alberta, Manitoba, and Saskatchewan in Canada. The species was described in 1965 by Turnbull, Dondale, and Redner. As a member of the genus Xysticus, it exhibits the characteristic crab-like body form and ambush hunting behavior typical of ground crab spiders.
Xysticus ampullatus
Xysticus ampullatus is a crab spider species in the family Thomisidae, first described in 1965. It is distributed across the United States and Canada, with confirmed records from Manitoba. As a member of the genus Xysticus, it belongs to a group of ground-dwelling ambush predators commonly known as ground crab spiders.
Xysticus apachecus
Xysticus apachecus is a species of crab spider in the family Thomisidae, first described by Gertsch in 1933. Like other members of the genus Xysticus, it is a ground-dwelling ambush predator characterized by its crab-like leg posture and sideways movement. The species is known from the United States, though specific details about its ecology and behavior remain limited in the published literature.
Xysticus aprilinus
Xysticus aprilinus is a species of ground crab spider in the family Thomisidae, first described by Bryant in 1930. The genus Xysticus comprises ambush-hunting spiders characterized by their laterally flattened bodies and enlarged front legs adapted for seizing prey. As with other members of this genus, X. aprilinus likely employs a sit-and-wait hunting strategy rather than building webs to capture prey. The species epithet 'aprilinus' suggests a possible association with spring activity, though this has not been formally documented.
Xysticus auctificus
Xysticus auctificus is a species of ground crab spider in the family Thomisidae, distributed across north-central North America. As a member of the genus Xysticus, it exhibits the characteristic crab-like leg arrangement and ambush hunting strategy typical of this diverse spider group. The species has been documented in prairie and grassland habitats, where it relies on crypsis to capture prey.
Xysticus bicuspis
Xysticus bicuspis is a species of ground crab spider in the family Thomisidae. The genus Xysticus comprises ambush predators commonly known as ground crab spiders, which typically hunt without webs. Xysticus species are distinguished from similar crab spiders in the genus Coriarachne and Misumena by morphological features and habitat preferences. This species has been recorded from the northern United States and southern Canada, including Montana, Manitoba, and Saskatchewan.
Xysticus californicus
Xysticus californicus is a species of crab spider in the family Thomisidae, first described by Keyserling in 1880. The species occurs in the United States and Mexico. As a member of the genus Xysticus, it belongs to a group of spiders commonly known as ground crab spiders, which are characterized by their ambush hunting strategy and crab-like leg posture.
Xysticus canadensis
Canada ground crab spider
Xysticus canadensis is a species of ground crab spider in the family Thomisidae, first described by Gertsch in 1934. It is distributed across northern North America and extends into Russia. As a member of the genus Xysticus, it exhibits the characteristic ambush-hunting behavior and flattened body form typical of ground crab spiders. The species overwinters as an adult or immature, emerging in early spring to hunt and reproduce.
Xysticus chippewa
Xysticus chippewa is a crab spider species in the family Thomisidae, first described by Gertsch in 1953. As a member of the genus Xysticus, it is a ground-dwelling ambush predator that does not construct webs to capture prey. The species occurs in northern North America, with records from the Canadian provinces of Alberta, Manitoba, and Saskatchewan. Like other Xysticus species, it has been observed engaging in ballooning behavior for dispersal.