Liphistiidae

Liphistiidae
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female Ryuthela tanikawai
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Arachnida
Order:	Araneae
Suborder:	Mesothelae
Family:	Liphistiidae Thorell, 1869
Genera
See text.
Diversity
8 genera, 96 species
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The spider family Liphistiidae comprises 8 genera and about 100 species from Southeast Asia, China, and Japan. They are among the most basal living spiders, belonging to the suborder Mesothelae. In Japan, the kimura-gumo (Heptathela kimurai) is rather well-known.

Biology

File:Heptathela.kimurai.yanbaruensis.burrow.-.tanikawa.jpg

Burrow of Heptathela kimurai

Liphistiidae are rarely seen, tube-dwelling spiders that construct rudimentary trap-doors, characterized by their downward pointing, daggerlike chelicerae, and by having a segmented series of plates on the upper surface of their abdomens. Some make silk trip-lines radiating away from the burrow entrance. They are active at night and live for many years, and females molt after maturity. Adult males wander in search for females, which rarely leave their burrows. The respiratory system consists only of book lungs, which could be a reason why these spiders show a quite low level of activity. In the past they were frequently believed to lack venom entirely, but in 2010 it was shown that at least Liphistius do have venom glands.

Although most species live in burrows, cave-dwelling species also fasten their retreats to the cave walls. Both burrows and retreats are sealed with woven doors.

Malaysian species

In caves in Malaysia, three different species of Liphistius are known, and each species is endemic to just one or two caves. The most well known of them is Liphistius batuensis, which is found in Batu Caves. Other species that can be found in Malaysia include Liphistius malayanus, Liphistius murphyorum and Liphistius desultor which can be found in cool-humid places.

The Malaysian trapdoor spiders are protected by local law. Continuous threats come from loss of habitat and collection by exotic pet traders. It is believed that most of the species are endemic henceforth once an isolated habitat is destroyed, the species might go into extinction.

Systematics

Although they have downward pointing chelicerae, like the Mygalomorphae, there is no close relationship between those two. It is thought that the common ancestor of all spiders was orthognath, and that in the Opisthothelae, comprising Mygalomorphae (mostly tarantulas) and Araneomorphae (all other spiders), only the Araneomorphae changed their alignment of chelicerae, while the mygalomorphs retained this symplesiomorphic feature.

Ryuthela secundaria

As of November 2015, the World Spider Catalog accepted the following extant genera:

• Ganthela Xu & Kuntner, 2015
• Heptathela Kishida, 1923 — Vietnam, Japan, China
• Liphistius Schiødte, 1849 — Southeast Asia
• Qiongthela Xu & Kuntner, 2015
• Ryuthela Haupt, 1983 — Ryukyu Islands, Okinawa
• Sinothela Haupt, 2003
• Songthela Ono, 2000
• Vinathela Ono, 2000

One genus of fossil spiders has been placed in this family:

• †Cretaceothele Wunderlich, 2015

Fossil record

While some Carboniferous fossil spiders have been assigned to Mesothelae, the only fossil to be explicitly placed in the family Liphistiidae is Cretaceothele lata Wunderlich, 2015 from the Cretaceous Burmese amber of Myanmar. The fossil genus was diagnosed as having an eye-field wider than that in living species.

See also

• List of Liphistiidae species
• Spider families

References

• Coddington, J.A. & Levi, H.W. (1991): Systematics and Evolution of Spiders (Araneae). Annu. Rev. Ecol. Syst. 22: 565-592. doi:10.1146/annurev.es.22.110191.003025
• Ono, H. (1999) Spiders of the genus Heptathela (Araneae, Liphistiidae) from Vietnam, with notes on their natural history. The Journal of Arachnology 27(1): 37-43. PDF
• Murphy, Frances & Murphy, John (2000): An Introduction to the Spiders of South East Asia. Malaysian Nature Society, Kuala Lumpur.
• Haupt, J. (2004): The Mesothelae - a monograph of an exceptional group of spiders (Araneae: Mesothelae). Zoologica 154: 8. ISSN 0044-5088, ISBN 3-510-55041-2 — Abstract

External links

http://www.arkive.org/search-taxonomy.html?q=Liphistiidae&requiredfields=Search_Family:Liphistiidae&client=arkive-info&site=arkive-info&related=Family&commonName=Trapdoor%20spider&latinName=Liphistius%20kanthan&returnURL=trapdoor-spider/liphistius-kanthan/info.html