Home > Phylum selection > Arthropoda > Araneae > Atypidae
Home How to cite this site Terms & conditions Disclaimer Contact Site tutorial / Help Links	Familia Atypidae General information Purse-web spiders are relatively large and very robust spiders. Their general appearance is similar to tropical bird spiders and indeed they belong to the same group of basal spiders, the Mygalomorphae. Characteristics of the Mygalomorphae are the possession of two pairs of book lungs (higher spiders have only one pair of book lungs, while the second breathing organ is a tracheal system) and the orthognathous chelicerae (i.e. the claws project forward and not sideways as in labidognathous spiders). The Atypidae have extraordinarily strong and large chelicerae and a heavily sclerotized prosomal shield that is reminiscent of the carapace of crabs. The species that occur in Germany are dark brown or black and about 10-15 mm long (the males are a bit smaller). Purse-web spiders build tubes in loose soil that are lined on the inside with silk. This subterranean portion of the tube can lead up to a meter deep in the ground. The silk lining protudes from the tube and forms a silk sack on the surface. This sack is camouflaged by the spider with detritus, plant parts and earth crumbs and thus resembles a plant root or decaying plant parts. When prey crawls or lands on this camouflaged external portion of the silk tube, the spider in the subterranean portion darts out and grabs the prey through the silk sack. Then the spider rips a hole in the external silk sack, wraps the prey in it and carries the immobilized prey into the subterranean part of the tube. Later the spider returns to the surface and repairs the hole in the external silk sack and also refits the camouflage of the sack. Dispersal only takes place during nymphal stages in the springtime (see also below); soon after this dispersal phase the spiderlings build their own tubes in which they spend most of their life. In Central Europe, the juveniles take 4 years to reach maturity in late July to September (depending on the species) of the fourth year. Females stay in their tubes after reaching sexual maturity, but the mature males leave their tubes and search for the tubes of females. By drumming a specific rhythmic pattern with their legs and pedipalps on the external silk sack of the female the males are able to enter the tube of the female without being mistaken for prey. The pair then mates and lives together in the same tube until the onset of winter. Then the male dies or is eaten by the female. The female then produces an egg sac and the young spiders hatch in late summer. These juveniles remain with the mother over winter until they leave the tube and spread to new areas in the springtime of the following year. Thus, the time span between mating and spreading of the juveniles is about 18 months. The juveniles mainly spread by "balooning", i.e. they produce long silk threads that catch wind gusts and take the spiderlings to air. The females are very long-lived and can mate several times in their live. They can live up to 10 years, whereas the males do not survive their maturity for very long and, thus, rarely get much older than 4 years. The German species prefer sandy or limy soil often along forest edges with dense vegetation. The animals need sunny, dry and warm slopes to build their tubes, but the steepness of the slopes differs from species to species. Some species can use only slightly oblique surfaces, while others require steep slopes of well over 45°. If an Atypidae spider is threatened or teased out of its tube, it shows a special defensive behavior. The spider lifts its prosoma and first leg pair and displays its huge chelicerae with its claws. This view is impressive enough to intimidate virtually every predator. This page has been updated on December 17, 2012 This site is online since May 31, 2005 Copyright © by Nikola-Michael Prpic. All rights reserved.	Species list References