Ozyptila atomaria, Greater leaflitter crab spider

Ozyptila atomaria (Panzer, 1801) (Greater leaflitter crab spider)

≤ 1900

1901-1979

1980-2005

2006 ≤

Description: Ozyptila atomaria is one of the larger species in the genus. The male carapace is dark reddish brown with wide black submarginal bands. Dorsum of abdomen greyish brown with indistinct darker spots. Front and sides whitish. The tibial apophysis is blunt. The legs are reddish-brown. The clavate hairs on the carapace and abdomen are absent in males (very small in females). The female carapace is yellowish brown and the submarginal bands less distinct than i males. Dorsum of abdomen is light brown with only a few dark, scattered spots. The legs are light brown in the female. Size: Female 4.5-6.5 mm; male 3-4.5 mm.

Genus: Ozyptila Simon, 1864. (Leaflitter crab spiders). Characters of genus: The members of this genus have colours and markings that make them resemble species of the Xysticus genus. However, they differ by being smaller, by having the median ocular trapezium longer than broad and by having the head protruded from thorax so that the carapace appear less circular. In addition they have only two pairs of ventral spines on tibia I and II, and the body is clothed with clavate hairs. These break off fairly easily, and may therefore be lacking. In some species the setae are very small and difficult to see with a lens. The abdomen is without a folium but with spots and transverse bars. Femur I is often swollen on prolateral side. Legs III and IV are only slightly shorter than I and II. Males are usually darker than females and more compactly bodied. This is in contrast to most other spider species where males usually are more slender and long-legged compared to females.

Family: Thomisidae Sundevall, 1833 (Typical Crab Spiders). Characters of family: The thomisids belong to the group of araneomorph, ecribellate spider families having 8 eyes and 2 tarsal claws. The eyes are arranged in two recurved rows of four with the posterior row usually more curved than the anterior row. The median eyes are the smallest, the laterals on confluent tubercles, with the posterior laterals facing somewhat backwards. The secondary eyes are provided with tapetum. Thomisids belong to a morphologically very diverse family of spiders generally characterized by broad, moderately flattened carapace and abdomen. The carapace is about as long as wide being semicircular, ovoid or slightly elongated sometimes with protuberances. Usually, it is thinly covered by a few erect simple or clavate setae sometimes arising from warts. Most species have lateral bands on the carapace; sometimes the bands reach the edge. The sternum is heart-shaped. Chelicerae are relatively small and weak, adapted for quick kills by biting prey in the head. Cheliceral teeth are absent except in one subfamily. Sometimes there are small teeth (denticles) present on promargin. Endites and labium are frequently longer than wide. Legs I and II are longer and sturdier than legs III and IV. Legs articulate in plane of the body (laterigrade legs). The anterior legs are often provided with series of strong spines on tibia and metatarsi (e.g. Xysticus and Ozyptila). The abdomen is variable in shape and colour. It may be round, ovoid or elongate, nearly always widest at rear half. It is often covered by scattered simple setae or clavate hairs. Abdominal colours vary from bright hues of white, yellow, green, and pink to shades of grey and brown in obscure patterns. The anterior spinners are short and conical and situated close together. A colulus is present in front of the spinners. The tracheal spiracle is situated close to the spinners. The epigyne is small and weakly sclerotized in some species. The epigynes of Xysticus species can be highly variable in depth of sclerotization within the same species and females are therefore sometimes difficult to identify by examination of epigynes. The tibia of the male palp is provided with ventral and retrolateral apophyses. Embolus is often long and curved along the rim of the cymbium.

Male

Female

Male