Cyclocosmia

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Cyclocosmia
A female cyclocosmia with her distinctive abdomen

A female cyclocosmia with her distinctive abdomen

Systematics
Class : Arachnids (arachnida)
Order : Spiders (Araneae)
Subordination : Tarantulas (Mygalomorphae)
Family : Halonoproctidae
Genre : Cyclocosmia
Scientific name
Cyclocosmia
Ausserer , 1871

Cyclocosmia is a genus of tarantula- like spiders in the Halonoproctidae family.

The conspicuously truncated abdomen (Opisthosoma) of the species of this genus is used to close a tunnel 7 to 15 centimeters high. The cyclocosmia species can be distinguished by the patterns on the discs, the number of hairs on the edge of the disc and the shape of the spermathec .

distribution

The seven cyclocosmia can be found in Asia and America. The distribution and relationship suggests that the genus existed before the division of Laurasia and that the Asian and American species were later geographically separated.

features

Cyclocosmia differs from all other Trapdoor Spiders by their two rows of eyes and their truncated abdomen, the caudal end of which forms a disc with ribs and furrows. Males are similar to females, their abdomen is also truncated caudally, but in most cases the disc is curved outward instead of flat. The carapace of the females is smooth and shiny, that of the males reticulate with a dull sheen. It is sparsely covered with hair and soft bristles. The strong chelicerae with a conspicuous, prickly rastellum have uneven rows of teeth on both edges. The legs of the females are short and strongly studded with spines, the legs of the males are longer and less prickly. While females show no leg scopula , all male tarsi are densely hairy.

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

Differentiation from similar genera

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, the abdomen of Galeosoma is straight , like Cyclocosmia , but does not show any ribs or furrows. Idiosoma shows ribs or furrows, but is only moderately truncated.

Way of life

Like all Trapdoor Spiders, the species of this genus are extremely local and rarely leave their caves. They are particularly at risk from predators or parasites that specialize in tracking down and penetrating caves. While other species camouflage their building entrances or create extra closed side chambers, the Cyclocosmia species close the entrance with the hard, strongly sclerotized , ribs and furrows stabilized disc of their abdomen when crawling into the cave . The disc fits tightly to the round walls of the cave and thus forms an impenetrable closure of the cave.

Because of the successful camouflaging of their trapdoor, Cyclocosmia species are difficult to find and collect, hence they are often considered to be some of the rarest spiders. Cyclocosmia are very long-lived; in captivity , specimens were over 12 years old.

species

The World Spider Catalog currently lists 10 species for the genus Cyclocosmia . (As of December 2018)

photos

  • The prominent abdomen is used to close the cave

  • Drawing of the spider

Individual evidence

  1. ↑ a b c d e Zhu, MS Z; Zhang, JX; Zhang, F .: Rare spiders of the genus Cyclocosmia (Arachnida: Araneae: Ctenizidae) from tropical and subtropical China. The Raffles Bulletin of Zoology 54 (1), 2006, pp. 119-124.
  2. ↑ a b c d Gertsch, Willis J .; Platnick, Norman I .: A revision of the trapdoor spider genus Cyclocosmia (Araneae, Ctenizidae). American Museum novitates 2580, 1975 ( abstract )
  3. ↑ Natural History Museum of the Burgergemeinde Bern: World Spider Catalog Version 19.5 - Cyclocosmia . Retrieved December 22, 2018.

Web links

Commons : Cyclocosmia  - Collection of pictures, videos and audio files

Cyclocosmia in the World Spider Catalog