Linyphiidae

Linyphiidae
	Drapetisca alteranda
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Arthropoda
Subphylum:	Chelicerata
Class:	Arachnida
Order:	Araneae
Infraorder:	Araneomorphae
Superfamily:	Araneoidea
Family:	Linyphiidae; Blackwall, 1859
Subfamilies
	Dubiaraneinae; Erigoninae; Leptyphantinae; Linyphiinae; Micronetinae; Mynogleninae; "Stemonyphantinae"
Diversity
	570 genera, >4.300 species

Linyphiidae is a family of very small spiders, including more than 4,300 described species in 601 genera worldwide.^[3] This makes Linyphiidae the second largest family of spiders after the Salticidae. New species are still being discovered throughout the world, and the family is poorly known. Because of the difficulty in identifying such tiny spiders, there are regular changes in taxonomy as species are combined or divided.

Spiders in this family are commonly known as sheet weavers (from the shape of their webs), or money spiders (in the United Kingdom, Ireland, Australia, New Zealand, and in Portugal, from the superstition that if such a spider is seen running on you, it has come to spin you new clothes, meaning financial good fortune).

There are six subfamilies, of which Linyphiinae (the sheetweb spiders), Erigoninae (the dwarf spiders), and Micronetinae, contain the majority of described species.

Common genera include Neriene, Lepthyphantes, Erigone, Eperigone, Bathyphantes, Troglohyphantes, the monotypic genus Tennesseellum and many others. These are among the most abundant spiders in the temperate regions, although many are also found in the tropics. The generally larger bodied members of the subfamily Linyphiinae are commonly found in classic "bowl and doily" webs or filmy domes. The usually tiny members of the Erigoninae are builders of tiny sheet webs. These tiny spiders (usually 3 mm or less) commonly balloon even as adults and may be very numerous in a given area on one day, only to disappear the next. Some males of the erigonines are exceptional, with their eyes set up on mounds or turrets. This reaches an extreme in some members of the large genus Walckenaeria, where several of the male's eyes are placed on a stalk taller than the carapace.

A few spiders in this family include:

Bowl and doily spider, Frontinella communis
Filmy dome spider, Neriene radiata
Blacktailed red sheetweaver, Florinda coccinea
Orsonwelles, a genus of giant Hawaiian linyphids containing the largest linyphiid, O. malus.

Distribution

Spiders of this family occur nearly worldwide. In Norway many species have been found walking on snow at temperatures of down to -7 °C.

Taxonomy

The Pimoidae are the sister group to the Linyphiidae.^[1]

Many species have been described in monotypic genera, especially in the Erigoninae, which probably reflects the scientific techniques traditionally used in this family.^[1]

Predators

Among birds, goldcrests are known to prey on money spiders.^[4]

References

^ ^a ^b ^c Hormiga 2000
^ Cirrus Digital, Sheetweb Spider - Drapetisca alteranda
^ World Spider Catalog: Linyphiidae Blackwall, 1859
^ RSPB Birds magazine, Winter 2004

Footnotes

Hormiga, G. (1998). The spider genus Napometa (Araneae, Araneoidea, Linyphiidae). Journal of Arachnology 26:125-132 PDF
Hormiga, Gustavo (2000): Higher Level Phylogenetics of Erigonine Spiders (Araneae, Linyphiidae, Erigoninae). Smithsonian Contributions to Zoology 609. (160 pages) PDF
Bosselaers, J & Henderickx, H. (2002) A new Savignia from Cretan caves (Araneae: Linyphiidae). Zootaxa 109:1-8 PDF
Hågvar, S. & Aakra, K. 2006. Spiders active on snow in Southern Norway. Norw. J. Entomol. 53, 71-82.
Platnick, Norman I. (2007): The world spider catalog, version 8.0. American Museum of Natural History.