A predatory, air-breathing arachnid (order Araneae) with eight legs and a body divided into two parts, a prosoma covered by a carapace, linked by a narrow pedicel to the opisthosoma (abdomen). The prosoma bears up to eight eyes, two large chelicerae (mouthparts) ending in fangs each connected to a poison gland, and pedipalps that serve different functions in different species. The opisthosoma bears spinnerets from which the spider extrudes silken thread. Most spiders feed on small arthropods, but some large species take tadpoles, small fish, nestling birds, and other vertebrates. There are two suborders, with about 114 families, 4000 genera, and 46,000 species, found worldwide except in Antarctica.