Spiders are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat with the exceptions of air and sea colonization. As of May 2021, at least 49,800 spider species in 129 families have been recorded by taxonomists. However, there has been dissension within the scientific community as to how all these families should be classified, as evidenced by the over 20 different classifications that have been proposed since 1900. Anatomically, spiders differ from other arthropods in that the usual body segments are fused into two tagmata, the prosoma, or cephalothorax, and opisthosoma, or abdomen, and joined by a small, cylindrical pedicel. Unlike insects, spiders do not have antennae.
About Spiders
3D science fiction film about a species of poisonous spiders discovered when a discarded space station crashes in New York City. The spiders mutate and create havoc in the city.
Achievement of Spiders
The spiders were predominantly computer-generated, but a 3-foot-long spider claw was used for some shots.
Top Facts You Did Not Know About Spiders
Glossary of spider terms - This glossary describes the terms used in formal descriptions of spiders; where applicable these terms are used in describing other arachnids. Links within the glossary are shown in this style.. Identifying spiders - Spider taxonomy is that part of taxonomy that is concerned with the science of naming, defining and classifying all spiders, members of the Araneae order of the arthropod class Arachnida with about 46,000 described species.. Arachnidism - A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound or severe pain.. Toxins - A toxin is a harmful substance produced within living cells or organisms; synthetic toxicants created by artificial processes are thus excluded. The term was first used by organic chemist Ludwig Brieger, derived from the word toxic.. Carboniferous arachnids.. Spiders.. Extant Pennsylvanian first appearances.. Taxa named by Carl Alexander Clerck.
