atypical tarantula
   HOME

TheInfoList



OR:

Atypidae, also known as atypical tarantulas or purseweb spiders, is a spider family containing only three genera. They are accomplished ambush predators that spend most of their time in a sock-like, silken retreat on the ground from where they kill their prey.


Distribution

'' Sphodros'' and '' Atypus'' occur in North America, while '' Atypus'' and '' Calommata'' occur in Asia and Africa. Only '' Atypus'' species are found in Europe. '' Atypus affinis'', '' Atypus muralis'', and '' Atypus piceus'' are the only
mygalomorph The Mygalomorphae, or mygalomorphs, are an infraorder of spiders, and comprise one of three major groups of living spiders with over 3000 species, found on all continents except Antarctica. Many members are known as trapdoor spiders due to t ...
spiders found in northwestern Europe.


Biology

''Atypus'' builds a
silken Silk is a natural protein fiber, some forms of which can be woven into textiles. The protein fiber of silk is composed mainly of fibroin and is produced by certain insect larvae to form cocoons. The best-known silk is obtained from the coc ...
tube parallel to the surface of the ground. While up to 8 cm of the tube lie on the ground, about 20 cm are buried vertically. The spider rests at the bottom of the tube. When prey walks on the exposed part, the spider, alerted by the vibrations, stabs the prey through the silk, cuts the web and drags the prey inside to be eaten. ''Calommata'' species, instead of building a purse web, live in burrows. ''Sphodros'' spp. usually prop their tubes against a tree trunk. Atypical tarantulas have huge
chelicerae The chelicerae () are the mouthparts of the subphylum Chelicerata, an arthropod group that includes arachnids, horseshoe crabs, and sea spiders. Commonly referred to as " jaws", chelicerae may be shaped as either articulated fangs, or similarl ...
for their size and relatively long
spinnerets A spinneret is a silk-spinning organ of a spider or the larva of an insect. Some adult insects also have spinnerets, such as those borne on the forelegs of Embioptera. Spinnerets are usually on the underside of a spider's opisthosoma, and are ...
(although not as long as those found in diplurids). The males are sometimes brightly colored and wander around looking for females in their tubes. The females are reddish-brown or dark-colored. During the breeding season for ''A. affinis'', the male leaves his own burrow and goes in search of females. When he finds the burrow of a female, he tentatively taps on the wall of the purse web, and if the female is receptive, he ventures into the confines of the burrow. The two spiders mate and cohabit until the male dies, when the female eats him. The female makes an egg sac and hangs it in her burrow. The next summer, the eggs hatch, and the spring after that, the spiderlings leave their mother's burrow and wander off to find a suitable place to build a lair of their own. Southeast Asian ''Atypus'' species have a body length of 7 to 21 mm in females, and about 12 mm in males. ''Calommata'' spp. of this region grow from 23 to 30 mm in females, and only about 7 mm in males.


Genera

, the
World Spider Catalog The World Spider Catalog (WSC) is an online searchable database concerned with spider taxonomy. It aims to list all accepted families, genera and species, as well as provide access to the related taxonomic literature. The WSC began as a series of ...
accepts the following genera: *'' Atypus'' Latreille, 1804 — Britain to Ukraine, Asia, North Africa, United States *'' Calommata'' Lucas, 1837 — Asia, South Africa *'' Sphodros''
Walckenaer Baron Charles Athanase Walckenaer (25 December 1771 – 28 April 1852) was a French civil servant and scientist. Biography Walckenaer was born in Paris and studied at the universities of Oxford and Glasgow. In 1793 he was appointed head of t ...
, 1835
— North America


See also

* List of Atypidae species


References


External links


Spiders of NW-Europe
{{Taxonbar , from=Q5895 Atypidae Mygalomorphae families