Linyphiidae
Encyclopedia
Linyphiidae is a family of spider
Spider
Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

s, including more than 4,300 described species
Species
In biology, a species is one of the basic units of biological classification and a taxonomic rank. A species is often defined as a group of organisms capable of interbreeding and producing fertile offspring. While in many cases this definition is adequate, more precise or differing measures are...

 in 578 genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 worldwide. 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
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 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
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, Ireland
Ireland
Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 and in Portugal
Portugal
Portugal , officially the Portuguese Republic is a country situated in southwestern Europe on the Iberian Peninsula. Portugal is the westernmost country of Europe, and is bordered by the Atlantic Ocean to the West and South and by Spain to the North and East. The Atlantic archipelagos of the...

, from the superstition
Superstition
Superstition is a belief in supernatural causality: that one event leads to the cause of another without any process in the physical world linking the two events....

 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 spider
Sheetweb spider
The sheetweb spiders are a subfamily, Linyphiinae, of sheet weavers. There are more than 800 described species.In some taxonomies, the subfamily Micronetinae is classified within Linyphiinae as the tribe Micronetini.-See also:...

s), Erigoninae (the dwarf spider
Dwarf spider
Erigoninae are the largest subfamily of sheet weavers , which is itself the second largest spider family. In the United States they are known as dwarf spiders, while they are called money spiders in England...

s), and Micronetinae, contain the majority of described species.

Common genera include Neriene
Filmy dome spider
The filmy dome spider is a sheet weaver: a spider in the family Linyphiidae. These spiders construct a dome of fine silk and hang upside-down under it, waiting for their prey....

, Lepthyphantes, Erigone
Erigone (genus)
Erigone is a genus of spiders of the araneomorphae sub-order and the Linyphiidae family. They are carnivorous, preying on small insects such as psylla and flies. The species of the genus are native to America, Europe, Asia, Africa and Oceania...

, Eperigone, Bathyphantes, Troglohyphantes
Troglohyphantes
Troglohyphantes is a genus of spider in the Linyphiidae family. At least some species are found exclusively in caves.-Name:The genus name is combined from Ancient Greek troglo- "cave " and -hyphantes, a common ending for linyphiid genera.-Species:-References: : , version 8.5. American Museum of...

, 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 on the next. Some males of the erigonines are very strange, with their eyes set up on mounds or turrets. This reaches an extreme in some members of the large genus Walckenaeria
Walckenaeria
Walckenaeria is a large spider genus in the family Linyphiidae.Some males of the erigonines are very strange, with their eyes set up on mounds or turrets...

, where several of the male's eyes are placed on a stalk taller than the carapace
Carapace
A carapace is a dorsal section of the exoskeleton or shell in a number of animal groups, including arthropods such as crustaceans and arachnids, as well as vertebrates such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron.-Crustaceans:In crustaceans, the...

.

A few spiders in this family include:
  • Bowl and doily spider
    Bowl and doily spider
    The bowl and doily spider, Frontinella communis, is a species of sheet weaver found in North and Central America. It is a small spider, about 4 mm long, that weaves a fairly complex sheet web system consisting of an inverted dome shaped web, or "bowl", suspended above a horizontal sheet web,...

    , Frontinella communis
  • Filmy dome spider
    Filmy dome spider
    The filmy dome spider is a sheet weaver: a spider in the family Linyphiidae. These spiders construct a dome of fine silk and hang upside-down under it, waiting for their prey....

    , Neriene radiata
  • Blacktailed red sheetweaver
    Blacktailed red sheetweaver
    Florinda coccinea is a species of web-building spider belonging to the family Linyphiidae. It is sometimes known as the black-tailed red sheetweaver or the red grass spider. This species is common in the southeastern United States, inhabiting grasslands, lawns and agricultural fields -Description:F...

    , Florinda coccinea

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
Pimoidae
The Pimoidae spider family is a rather small group of 37 species in four genera. They are monophyletic, and probably closest related to the Linyphiidae.-Distribution:...

 are the sister group to the Linyphiidae.

Many species have been described in monotypic
Monotypic
In biology, a monotypic taxon is a taxonomic group with only one biological type. The term's usage differs slightly between botany and zoology. The term monotypic has a separate use in conservation biology, monotypic habitat, regarding species habitat conversion eliminating biodiversity and...

 genera
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

, especially in the Erigoninae, which probably reflects the scientific techniques traditionally used in this family.

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.

External links

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