Definition of Endangered:

An endangered species is “a species at risk of extinction because of human activity, changes in climate, changes in predator-prey ratios, etc., esp. when officially designated as such by a governmental agency such as the U.S. Fish and Wildlife Service”[1]. A spider is a member of the order Araneae, one of many orders within the class arachnid; meaning it has a body consisting of two segments: a cephalothorax, and an abdomen. Spiders are distinct from insects because they have eight legs, instead of six. All spiders are predators that feed off insects, and some larger species have been known to catch small reptiles, birds, and amphibians (Levi and Levi, 2002). The Siberian Tiger, a subspecies of tiger. ... The USFWS logo The United States Fish and Wildlife Service is a unit of the United States Department of the Interior that is dedicated to managing and preserving wildlife. ... Diversity 111 families, 40,000 species Suborders Mesothelae Mygalomorphae Araneomorphae  See table of families Closeup image of a Wolf Spider Wikispecies has information related to: Spiders Spiders are predatory invertebrate animals that have two body segments, eight legs, no chewing mouth parts and no wings. ... Extant orders Acarina Amblypygi Araneae Opiliones Palpigradi Pseudoscorpionida Ricinulei Schizomida Solifugae Uropygi Arachnids are a class (Arachnida) of joint-legged invertebrate animals in the subphylum Chelicerata. ... The cephalothorax is an anatomical term used of arachnid and malacostracan arthropods for the first major body section. ... The abdomen is a part of the body. ... This snapping turtle is trying to make a meal of a Canada goose, but the goose is too wary. ... Orders Subclass Apterygota Symphypleona - globular springtails Subclass Archaeognatha (jumping bristletails) Subclass Dicondylia Monura - extinct Thysanura (common bristletails) Subclass Pterygota Diaphanopteroidea - extinct Palaeodictyoptera - extinct Megasecoptera - extinct Archodonata - extinct Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Blattodea (cockroaches) Mantodea (mantids) Isoptera (termites) Zoraptera Grylloblattodea Dermaptera (earwigs) Plecoptera (stoneflies) Orthoptera (grasshoppers, crickets... Orders  Crocodilia - Crocodilians scary crocodiles. ... For other meanings of bird, see bird (disambiguation). ... For other uses, see Amphibian (disambiguation). ...

Endangered spiders

Until recently, insects and arachnids have not been considered for inclusion on threatened and endangered species lists. It was not until approximatly 1994 that most invertebrates were even recognized as being just as vulnerable as other charismatic fauna. It is because of this that there are very few species of spiders listed as threatened or endangered and many are simply listed as “undetermined”, i.e. the spiders population numbers are unknown. [2]. {{Taxobox | color = pink | name = Insects | fossil_range = Carboniferous - Recent | image = European honey bee extracts nectar. ... Extant orders Acarina Amblypygi Araneae Opiliones Palpigradi Pseudoscorpionida Ricinulei Schizomida Solifugae Uropygi Arachnids are a class (Arachnida) of joint-legged invertebrate animals in the subphylum Chelicerata. ... The Siberian Tiger, a subspecies of tiger. ... Invertebrate is a term that describes any animal without a spinal column. ... Fauna is a collective term for animal life of any particular region or time. ... In biology, a species is one of the basic units of biodiversity. ... Diversity 111 families, 40,000 species Suborders Mesothelae Mygalomorphae Araneomorphae  See table of families Closeup image of a Wolf Spider Wikispecies has information related to: Spiders Spiders are predatory invertebrate animals that have two body segments, eight legs, no chewing mouth parts and no wings. ... An endangered species is a species whose population is so small that it is in danger of becoming extinct. ...

Listed species

While few organizations agree completely on which spiders are endangered or threatened, a few commonly listed species are the Spruce-fir moss spider, the Dolloff cave spider, the Great Raft spider, and the Kauai cave wolf spider. Binomial name Microhexura montivaga (, ) Spruce-fir moss spiders (Microhexura montivaga) are an endangered species of spider found at high elevations in the southern Appalachian Mountains. ...

Spruce-fir moss spider (Microhexura montivaga)

This species is federally listed as endangered under the Endangered Species Act of 1973. Very simply, this spider can be described as being a tiny “tarantula” with adults measuring in at only 2.5 to 3.8 millimeters. This particular species inhabits high-elevation forests in western North Carolina and eastern Tennessee. Because the species is extremely vulnerable to desiccation, it can only be found in damp shady areas such as shaded moss. The spider builds a tube shaped web between the moss and a rock or fir tree (Fish and Wildlife service, 1995), hence the name: Spruce-fir moss spider. This article or section is in need of attention from an expert on the subject. ... Diversity 113 genera, 897 species Genera Subfamily Acanthopelminae    Acanthopelma Subfamily Aviculariinae    Avicularia    Ephobopus    Pachistopelma    Tapinauchenius Subfamily Eumenophorinae    Anoploscelus    Batesiella    Citharischius    Encyocrates    Eumenophorus    Hysterocrates    Loxomphalia    Loxoptygus    Monocentropus    Myostola    Phoneyusa    Polyspina Subfamily Harpactirinae    Ceratogyrus    Coelogenium    Eucratoscelus    Harpactira    Pterinochilus Subfamily Ischnocolinae    Chaetopelma    Cratorrhagus    Heterothele    Ischnocolus    Nesiergus    Plesiophrictus/Neoplesiophrictus Subfamily Ornithoctoninae    Citharognathus    Cyriopagopus    Haplopelma... Official language(s) English Capital Raleigh Largest city Charlotte Area  Ranked 28th  - Total 53,865 sq mi (139,509 km²)  - Width 150 miles (240 km)  - Length 560[1] miles (901 km)  - % water 9. ... Official language(s) English Capital Nashville Largest city Memphis Largest metro area Nashville Area  Ranked 36th  - Total 42,169 sq mi (109,247 km²)  - Width 120 miles (195 km)  - Length 440 miles (710 km)  - % water 2. ...

Dolloff cave spider (Meta dolloff)

While not listed as endangered, this spider is considered to be vulnerable to extinction. Much larger than Microhexura montivaga, this spider ranges in size from 10 to 15 millimeters. This species makes large orb shaped webs at the entrance of caves, and as of 2001 has only been found in caves located in Santa Cruz, California (Ubick, 2001). The Dodo, shown here in illustration, is an often-cited[1] example of modern extinction. ... Alternate meanings: Cave (disambiguation) The outside world viewed from a cave A cave is a natural underground void. ... Santa Cruz is the county seat and largest city of Santa Cruz County, California, United States. ...

Great Raft spider (Dolomedes plantarius)

The populations of Great Raft spiders have declined so much that one of only two populations is close to extinction. These two remaining populations can only be found in Great Britain and is one of its largest spiders and rarest animals. This spider is a semi-aquatic species and it's dependence on water may have led to their population declines. The information on the Great Raft spider is very recent and due to a lack of any historical records the level of decline can not be accurately measured (Smith, 2000). The Dodo, shown here in illustration, is an often-cited[1] example of modern extinction. ... In biology, a species is one of the basic units of biodiversity. ...

Kauai cave wolf spider (Adelocosa anops)

This spider is found only on the Hawaiian island of Kauai. In fact, as of 2006 this species can be found in only one cave on Kauai, only 16 to 28 individuals have ever been encountered. Compared to other spider species, the Kauai cave wolf spider has low reproductive rates, and due to habitat constraints, has little access to food sources (Fish and Wildlife service, 2006). This spider is one of the largest documented cave-dwelling organisms measuring up to a massive 8 centimeters. Because it spends its life in the darkness of a cave, this spider has no need for sight and is therefore completely eyeless (Krajick, 2001). Kauaʻi (usually spelled Kauai outside the Hawaiian Islands and pronounced kawa-ee) is the oldest and fourth largest of the main Hawaiian Islands, having an area of 1,430. ... In biology and ecology, an organism (in Greek organon = instrument) is a living being. ...

Reasons for population declines

Because of their small size and relatively fast reproductive rate, it is easy to believe that spiders are not as vulnerable to extinction as the well known megafauna. The references mentioned indicate otherwise. Spiders are extremely vulnerable to a wide variety of environmental factors ranging from food abundance to pesticide use to habitat destruction. The reasons for each population's decline is very species specific and can not be generalized. Due to such complexity, one can only assume that closer attention must be paid to the health of these small arthropods to ensure their survival into the future. The mammoth, an extinct genus of megafauna. ... An environment is a complex of external factors that acts on a system and determines its course and form of existence. ... A cropduster spreading pesticide. ... Habitat destruction is a process of land use change in which one habitat-type is removed and replaced with some other habitat-type. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - Trilobites (extinct) Subphylum Chelicerata Arachnida - Spiders, Scorpions, etc. ...

References

• Krajick, K. 2001. "Cave Biologists Unearth Buried Treasure". Science magazine. Vol. 293. Pp. 2378-2381.
• Levi, Herbert W. and Lorna R. Levi. 2002. Spiders and Their Kin. St. Martin's Press. New York, U.S.
• Smith, Helen. 2000. "The status and conservation of the fen raft spider (Dolomedes plantarius) at Redgrave and Lopham Fen National Nature Reserve, England". Biological Conservation. Vol. 95. Issue 2. Pp. 153-164.
• Ubick, Darrell. 2001. Cavernicolous invertebrates of Cave Gulch, Santa Cruz County, California. Department of Entomology, California Academy of Sciences. San Francisco.
• U.S. Fish and Wildlife Service. 2006. Recovery Plan for the Kauai Cave Arthropods: the Kauai Cave Wolf Spider (Adelocosa anops) and the Kauai Cave Amphipod (Spelaeorchestia koloana). U.S. Fish and Wildlife Service. Portland, Oregon. 64 pp.
• U.S. Fish and Wildlife Service. 1995. Endangered and Threatened Wildlife and Plants; Spruce-Fir Moss Spider Determined To Be Endangered. Federal Register. Vol.60. No. 24. Pp. 6968-6974