Uloboridae

Federfußspinne ( Uloborus plumipes )

  • Triangle spiders Hyptiotes
  • Federfußspinnen Uloborus

The cribellate ( Uloboridae ) are one of 94 families of the Real spiders. Your are attributed worldwide are currently 250 species in 18 genera. This cribellate spiders are widespread in the tropics. Only a few species also run northwards into the temperate zones. In Central Europe, only two genera represented (triangle spiders, Hyptiotes and Federfußspinnen, Uloborus ). In Latin America and the genus Philoponella is found, two species live in the socially in large colonies.

They have developed amazing Tarn, network construction and fishing methods. Cribellate have no venom glands and produce no glue threads. Adhesion of their cribellate fishing wool based on the structure of tens of thousands, 10-15 nm finest silk fibers that curl around stable scaffold strands.

Morphology of native species

The adult animals of domestic species Hyptiotes paradoxus ( CL Koch, 1834), Uloborus plumipes Lucas, 1846 and U. walckenaerius Latreille, 1806 are three to six millimeters long, have a moderately strong physique. The leg length of an individual is very different, the longest leg (leg pair I and II) can be twice as long as the body length, the pairs of legs III and IV are much shorter. The metatarsus IV is concave. The females there their calamistrum, which is reduced in the males. Cribellate have three tarsal claws. They have eight dark eyes in two horizontal lines of four eyes. The male Palpenorgane built complex and houses the hollow -shaped tarsal cymbium. The abdomen ( opisthosoma ) is strikingly patterned. The females have a plate-like cribellum in front of the spinnerets. The cribellum is reduced in the males.

Lifestyle and network construction

Cribellate are Tarnungsspezialisten, both in their natural form, as well as in life. They collect fragments of leaves and other material with which they disguise themselves, or see leaves or branches deceptively similar.

Specific and common characteristics of the networks of cribellate are the network hub that is narrow and intricately meshed, and the band-shaped ornaments or Stabilimente. The original function and origin of the stable elements that incorporate also some ecribellaten orb-weaving spiders (eg Argiope, Argiope spiders) is unclear. The Uloboridae it serves camouflage and increase the stability and may facilitate the repair of the damaged network. The most common form of stable Apartments is a serrated band that runs through the center of the orb web. It is almost invisible at the hub. However, there are numerous variations of this stable Apartments, such as V- shaped curve with the hub in the center or crosses, as well as complete or interrupted concentric circles.

The Kräuselradnetzspinne lurks with an upwardly directed side of the abdomen in the hub on the underside of its horizontal network. The legs are stretched forward and backward so that it connects the stable element to a complete event. In the light breeze it is almost indistinguishable from a branch. This Tarnmethode perfecting the females. Their elongated egg packages it up in a row over the net, which is additionally supplemented with prey remains and other debris, and stretched himself in between in the middle. The result is a bright line whose individual components are difficult to distinguish from each other, while the actual event can be seen even worse by the contrast.

Not all networks are horizontal, and not form a complete wheel In some species the net is slightly inclined, and in other more or less vertically. The application of vertical networks represents a significant environmental difference, as the spider does not have to wait for running or falling insects, but pushes the boundaries of the airspace of the flying insects. So changed the entire food spectrum, and thus the complete way of life. The Uloboriden were therefore previously often viewed as an evolutionary link between the bottom-dwelling spiders and the trappers in height.

The native to Central Europe species build in the crown and shrub layer their traps in which they hold head over a shirred signal thread that is attached to the network. This safety net sees the orb-web spiders of similar, but is adjusted horizontally (in Uloborus ), is made up of only three sectors ( at Hyptiotes ), or consists only of a broad band cribellater catching silk, as in the tropical Cane spider Miagrammopes.

Since cribellate have no venom glands and claws, with which the prey could be stunned or killed, this is woven from the Kräuselradnetzspinne only once.

Systematics and evolution

The Uloboridae and their closest relatives, the family of Deinopidae were, as long ancestors of the orb-weaving spiders ( Araneoidea ) viewed since the horizontal orb web woven of Deinopidae could have developed through the network of cribellate for vertical, free-hanging orb. The designs are very similar; as the network of real web spiders ( Araneoidae ) corresponds to a complete wheel in the sector spiders ( Zygiella ), two sectors seem to be missing that show up in the triangle spider, members of the cribellate again. Similarly, the stable elements appear in some networks on both superfamilies. The great accuracy, which have both the traps of orb-weaving spiders as well as the pitfalls of cribellate seems surprising enough to take on a unique development in the evolution of the order. Also, it appeared to the arachnologists plausible that the ability of ecribellaten spiders to provide the fishing silk with other different substances such as glue, it may have developed at this point of evolution. Therefore, the orb weavers were long considered descendants of cribellate.

Today, it is due to deepening studies assume that it is this complete or partial orb webs of very large superfamily of orb-weaving spiders and the cribellate is very similar principles, but which have developed independently. It is probably an analogy. This applies to the types of traps ( stable elements, orb webs, sector networks), but also for the development of glue threads. Also, she has repeatedly taken place in the evolution independently of each other (see: cribellate problem). Which ecological circumstance, it is thanks to them that the cribellate can dispense venom glands, initially remains unexplained.

Diagram of the relationships

( Development of ' modern spiders " )

Orb-weaving spiders ( Araneoidea )

Cribellate ( Uloboridae )

Deinopidae

Oecobiidae

Hersiliidae

Malkaridae

Local representatives

Only two members of the genus Uloborus and Hyptiotes have been detected paradoxus in Central Europe.

Swell

  • Norman I. Platnick, 2006. The World Spider Catalog, version 6.5. American Museum of Natural History.
  • Gertsch, Willis J. 1979: American Spiders, 2nd edition. Van Nostrand Reinhold, New York, ISBN 0-442-22649-7
  • Theo glance, Robert Bosmans Jan Buchar, Peter Gajdoš, Ambros Hänggi, Peter Van Helsdingen, Vlastimil Ružicka, Wojciech Starega & Konrad Thaler: Checklist of the spiders of Central Europe. Checklist of the spiders of Central Europe. (Arachnida: Araneae). Version 1 December 2004. Pdf, 1.41 MB
  • Coddington, Levi
  • Watson, L., and Dallwitz, M. J. 2004 onwards. The families of spiders Represented in the British Isles. Version: 23rd October, 2005.
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