Spiders

jyj EMBERS OF THE 101 families

_ and 40,000 species in the order

Araneae are distinguished by their general appearance and their ability to spin silk thread and make webs.

The cephalothorax is covered by a carapace and is joined to the abdomen by a stalk. The front part of the carapace carries the eyes. Most species have eight simple eyes, but some have six, four, or two eyes, or none at all. The chelicerae have a hinged fang at the tip, and almost all species have venom glands. A spider's pedipalps are six-segmented and have a sensory function. In males, they are also used to transfer sperm. There are four pairs of seven-segmented walking legs. The abdomen is not segmented and carries silk-spinning organs (known as spinnerets) and a genital opening called the epigyne. When a spider feeds, the body tissues of its prey are dissolved by enzymes in the spiders digestive juices, producing a liquid that it then sucks up. Typically, the round spider eggs are laid inside a silk sac, which some species carry until the young hatch.

Spiders are found in almost every terrestrial habitat, from deserts to mountain peaks. They cannot fly, but many are able to travel long distances by "ballooning" on silk threads.

0rder Arankak

Family AOKLKNIDAK

Funnel weavers

1 hese spiders have hairy bodies and often have long legs. The narrow front of the cephalothorax bears eight eyes and the oval, quite slender abdomen may have dark bars, chevrons, or spots. The two posterior spinnerets have two segments and are longer than the anterior ones. Typically, these spiders make a funnel-shaped retreat at the margin of a flat web. • LIFE CY( TE After mating, males and females may stay together until the male dies. The egg sac is covered with silk and debris and is kept in the web. The young may be fed with regurgitated food

•()<:< :i IRRENi:E Wofldwide. In is habitats, including grassland, meadows, and gardens. Webs arc made in bushes, among stones, on rocks and walls, under logs, and inside houses.

No. of species ^qq long, hairy legs

> posterior spinnerets

» uniform coloration

AGEEENOPSES SPKCIliS, or grass spiders, do not have distinct abdominal markings. Some larger species have been known to bite humans.

> posterior spinnerets

» uniform coloration

No. of species ^qq long, hairy legs

TEGENARIA GIG ANTE A is common in houses and gardens in parts of Europe. The large house spiders often found in domestic baths belong to this genus.

AGEEENOPSES SPKCIliS, or grass spiders, do not have distinct abdominal markings. Some larger species have been known to bite humans.

TEGENARIA GIG ANTE A is common in houses and gardens in parts of Europe. The large house spiders often found in domestic baths belong to this genus.

0rder ARANKAK

Family ARAN KI DAK

No. of species 4 000

mottled camouflage coloring

céphalothorax

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