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Encyclopedia > Cribellate

A cribellum is a kind of comb-like device in certain spiders, used to separate fibers of silk drawn from its spinnerets into many extremely fine fibers, giving it a wooly structure. Those fibers are so small in diameter that prey insects easily become entangled in them, without any glue needed. The spiders then bite them before they can get away. For other senses of this word, see silk (disambiguation). ... A spinneret is a spiders silk spinning organ. ... Long and short hair wool at the South Central Family Farm Research Center in Boonesville, Arizona Wool is the fibre derived from the fur of animals of the Caprinae family, principally sheep, but the hair of certain species of other mammals such as goats, alpacas and rabbits may also be... Historically, glue only refers to protein colloids prepared from animal tissues. ...


The cribellum is a functional homolog of the antorior median spinnerets of Mesothelae and Mygalomorphae, which do not have a cribellum. The Liphistiidae are the most primitive living spiders, placed in their own suborder, called the Mesothelae. ... Families Antrodiaetidae (folding trapdoor spider) Atypidae (atypical tarantula) Ctenizidae (trapdoor spider) Cyrtaucheniidae (wafer trapdoor spider) Dipluridae (funnel-web tarantula) Hexathelidae (venomous funnel-web tarantula) Mecicobothriidae (dwarf tarantulas) Theraphosidae (tarantula) The Mygalomorphae, (also called the Orthognatha), are an infraorder of spiders. ...


The presence or absence of a cribellum is used to classify araneomorph spiders into the cribellate and ecribellate (not cribellate) type. The distinction can be used to study evolutionary relationships. However, in 1967 it was found out that there are many families with both cribellate and ecribellate members.[1] It is today believed that the precursor of all Araneomorphae was cribellate (symplesiomorphy), and that this function was lost in some araneomorph spiders secondarily.[2] Many of these still retain a colulus, which is thought to be a reduced cribellum, and is of unknown function. Only about 180 genera in 23 families (1991) still contain cribellate members, although the the diverse Australian cribellate fauna is still mostly undescribed. However, that fauna may be an example of high diversity in Australian animals that are only relicts in other regions of the world, like the marsupials.[2] The Araneomorphae, previously called the Labidognatha, are a suborder of spiders. ... A symplesiomorphy or symplesiomorphic character is in cladistics a trait which is shared (a symmorphy) between two or more taxa, but which is also shared with other taxa which have an earlier last common ancestor with the taxa under consideration. ... Orders Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Marsupials are mammals in which the female typically has a pouch (called the marsupium, from which the name Marsupial derives) in which it rears its young through early infancy. ...


Cribellate taxa are not very speciose, and for nearly all cribellate-ecribellate sister clades the cribellate lineage is less diverse,[2] for example:

The Haplogynae are a series of araneomorph spiders. ... Genera Afrofilistata Andoharano Filistata Filistatinella Filistatoides Kukulcania Lihuelistata Microfilistata Misionella Pikelinia Pritha Sahastata Tricalamus Wandella Yardiella Zaitunia The crevice weaver spiders (family Filistatidae) contain primitive cribellate, haplogyne, weavers of funnel or tube webs. ... Diversity 2 families, 319 species Families Deinopidae Uloboridae The Uloboroidea are a superfamily of cribellate [1] araneomorph spiders. ... Diversity 14 families, 11155 species Families see text. ...

References

  1. ^ Lehtinen, P.T. (1967). Classification of the Cribellate spiders and some allied families, with notes on the evolution of the suborder Araneomorpha. Ann. Zool. Fennici 4:199-467
  2. ^ a b c Coddington, J.A. & Levi, H.W. (1991). Systematics and Evolution of Spiders (Araneae). Annu. Rev. Ecol. Syst. 22:565-592
  • Eberhard, William G. and Pereira, Flory. 1993. Ultrastructure of cribellate silk of nine species in eight families and possible taxonomic implications (Araneae: Amaurobiidae, Deinopidae, Desidae, Dictynidae, Filistatidae, Hypochilidae, Stiphidiidae, Tengellidae). Journal of Arachnology 21(3): 161-174. PDF
  • Huber, B.A. (1994): Spermophore morphology reveals a new synapomorphy of Oecobius and Uroctea (Araneae, Oecobiidae). Journal of Arachnology 22: 73-74. PDF
  • Griswold, C.E., Coddington, J.A., Platnick, N.I. and Forster, R.R. (1999). Towards a Phylogeny of Entelegyne Spiders (Araneae, Araneomorphae, Entelegynae). Journal of Arachnology 27:53-63. PDF

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