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Wikipedia / Liphistius

Liphistius is a genus of basal trapdoor spiders. It is the only genus in the subfamily Liphistiinae, one of the two subfamilies in the family Liphistiidae, which is the only family in the suborder Mesothelae. Species of Liphistius are found in Japan, China, and Southeast Asia.

Taxonomy

The genus Liphistius was erected by Jørgen M. C. Schiødte in 1849. Schiødte spelt the name Lipistius; this was corrected to Liphistius by Tamerlan Thorell in 1869, a change endorsed by the International Commission on Zoological Nomenclature in 1970. Liphistius is from Greek , ('lack') and , ('web' in this context).

Thorell erected the family Liphistiidae in 1869 for the genus Liphistius. Initially, it was the only family placed in the suborder Mesothelae. In 1923, Kyukichi Kishida described a new genus, Heptathela, and suggested creating two tribes within the Liphistiidae corresponding to the genera Liphistius and Heptathela. In 1939, Alexander Petrunkevitch raised the tribe Heptatheleae to a separate family, Heptathelidae, thus restoring the narrower circumscription of the Liphistiidae. In 1985, Robert Raven reunited the two families, a view supported by Xu et al. in 2021, Breitling in 2022, and Sivayyapram et al. in 2024. Liphistius is then the only genus in the subfamily Liphistiinae, the other subfamily being Heptathelinae. Other authors have maintained two separate families, a position not accepted by the World Spider Catalog .

Phylogeny

Molecular phylogenetic studies have repeatedly shown that the suborder Mesothelae is monophyletic, at least as regards extant (living) species, with the two subfamilies or families forming separate clades:

Biology

Liphistius species share features with the subfamily Heptathelinae. They are medium to large spiders. They have downward pointing, daggerlike chelicerae. Like other members of the suborder Mesothelae, and unlike all other extant spiders, they have a segmented series of plates (tergites) on the upper surface of all segments of the abdomen and their spinnerets are placed in the middle of the underside of the abdomen, rather than at the end. Their sternum (a plate on the underside of the cephalothorax) is narrow, and there is another smaller ventral plate (the sternite) between the fourth pair of legs. The carapace is mostly flat, though it can be slightly elevated near the head. The eyes are distinctly clustered together on a single nodule. The anterior median eyes are small, but the posterior median eyes are large and round. The lateral eyes are long and kidney-shaped. The distal leg segments have strong spines and three claws. The respiratory system consists only of book lungs, which could help explain why they are relatively inactive. Unlike heptathelines, the male palp has a tibial apophysis.

Female body lengths range from ; males are slightly smaller. They live in burrows in earthen banks, on some cave walls, and probably in forests. The burrow is sealed with a thin, circular, woven door, which is disguised with soil and moss. While they spend the day deep inside their burrows, at night they wait just below the door for insects, woodlice, and similar invertebrates that stumble over one of the seven silken lines that radiate from the entrance. Members of the subfamily Heptathelinae do not construct such signal lines. With a reluctance to leave their burrows, Liphistius species push up the door and reach for their prey. Adult males sometimes wander in search for females, but females rarely leave their burrows.

In the past, they were frequently believed to lack venom, but in 2010 it was shown that at least some Liphistius species have venom glands.

Species

, the World Spider Catalog accepted 81 species:

Threatened Malaysian species

Three of the Liphistius species known to exist in Malaysia are endemic to only one or two caves. The most well known is Liphistius batuensis, which is found in Batu Caves. It is endangered, with a population of under 250 individuals. Other species found in Malaysia include Liphistius malayanus, Liphistius murphyorum and Liphistius desultor. The Malaysian trapdoor spiders are protected by local law, though continuous threats come from loss of habitat and collection by exotic pet traders.

References

Further reading

  • Platnick, Norman I. & Sedgewick, W.C. (1984): A revision of the spider genus Liphistius (Araneae, Mesothelae). American Museum Novitates, (New York), No 2781, 31pp.

  • Whitten, T., Clements, R. & Price, L. 2013. Liphistius kanthan. In: IUCN 2013. IUCN Red List of Threatened Species. Version 2013.1. <www.iucnredlist.org>. Downloaded on 6 July 2013.