Cyclocosmia

A female Cyclocosmia with its distinctive abdomen

Cyclocosmia is a spider genus which belongs to the family of trapdoor spiders authentics ( Ctenizidae ).

The striking truncate abdomen of the species of this genus is used to close a tunnel 7-15 inches of height. Cyclocosmia the types can be distinguished, inter alia, to the patterns on the wafers, the number of hairs at the wafer edge and in the form of spermathecae.

Features

Cyclocosmia differs from all other authentics trapdoor spiders through their eyes arranged in two rows and the truncated abdomen ( opisthosoma ), the caudal end forms a ribbed and furrow slice. Males resemble the females, their abdomen is also truncated caudal, but the disc is in most cases curved outwards instead of flat. The carapace of the female is smooth and shiny, the males reticulate, with a matte finish. It is sparsely covered with hair and soft bristles. The strong chelicerae with a striking, spiky Rastellum wear on both edges uneven rows of teeth. The legs of the females are short, heavily studded with spines, the legs of the males are longer and less prickly. While females show no leg Scopula, all tarsi of the males are densely hairy.

Females reach a length of up to 39 mm (C. ricketti ), males up to 22 mm (C. loricata ).

Dissemination

The seven Cyclocosmia are found in Asia and America. The distribution and relationship suggests that the genus existed before the division of Laurasia and the Asian and American styles were later separated geographically.

Way of life

Like all authentics trapdoor spiders are also the species of this genus extremely localized and rarely leave their burrows. They are therefore particularly vulnerable to predators or parasites that specialize in the detection and intrusion into caves. While other types of camouflage their Baueingänge or extra- create closed side chambers, close the Cyclocosmia types while crawling into the cave the entrance with the hard, strongly sclerotized, stabilized by ribs and furrows butt of their abdomen. The washer fits in tight to the round walls of the cave, and thus forms an impenetrable closure of the cave.

Because of the successful camouflage its trap door are Cyclocosmia species are difficult to find and collect, so they are often regarded as some of the rarest spiders. Cyclocosmia are very durable, in captivity specimens were over 12 years old.

Demarcation from other genres

The genera Idiosoma and Galeosoma in the family Idiopidae show a similar shape of the abdomen, but are not closely related to Cyclocosmia. In addition to the different arrangement of the eyes of the abdomen of Galeosoma is precisely truncated as in Cyclocosmia, but shows no ridges or furrows. Idiosoma shows ridges or furrows, but is truncated only moderate.

The types

• Cyclocosmia lannaensis Schwendinger, 2005 - China, Thailand
• Cyclocosmia latusicosta Zhu, Zhang & Zhang, 2006 - China (previously only known from the type locality Aidian Village, Guangxi, near the Thai border)
• Cyclocosmia loricata ( CL Koch, 1842) - Mexico, Guatemala
• Cyclocosmia ricketti ( Pocock, 1901) - China ( Fujian, Hunan, Zhejiang, Sichuan )
• Cyclocosmia siamensis Schwendinger, 2005 - Thailand
• Gertsch & Platnick Cyclocosmia torreya, 1975 - USA
• Cyclocosmia truncata ( Hentz, 1841) - USA

Pictures

Drawing of the spider