Government Canyon bat cave spider Tayshaneta microps | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Arthropoda |
Subphylum: | Chelicerata |
Class: | Arachnida |
Order: | Araneae |
Infraorder: | Araneomorphae |
Family: | Leptonetidae |
Genus: | Tayshaneta |
Species: | T. microps |
Binomial name | |
Tayshaneta microps | |
Synonyms [1] | |
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Tayshaneta microps, synonym Neoleptoneta microps, is a rare species of spider in the family Leptonetidae known by the common name Government Canyon bat cave spider. It is endemic to Texas in the United States, where it is known to be found in two caves in Bexar County. It is one of two in its genus listed as endangered species in 2000. [2] It is a troglobite, an animal which spends its entire life in caves.
Tayshaneta microps has a hard light brown bristle bearing shell known as a carapace. Its legs are elongated and thin covered in hair-like structures called setae with few scattered spines. The abdomen is pale to yellow-brown and is also covered in setae. [3]
The typical body length is 1.35mm(0.053 inches) which can be divided into subparts. The caraspace - hard outer shell - is typically 0.64mm (0.0252inches) long and 0.56mm (0.022 inches) wide. The abdomen of the Tayshaneta microps is approximately 0.7mm (0.0276 inches) and 0.54mm (0.0213inches) wide.
Since Tayshaneta microps is a troglobite, it is difficult for scientists to capture and study them. The caves that these spiders reside in have more caves than entrances and ninety percent of them are closed off from human access. Therefore, scientists for the most part are unable to study these spiders.
According to Professor Joel Ledford of UC Davis, for the most part, there is no information currently available on Tayshaneta microps life history. [3]
Egg sacs for another related species only contained a few eggs. No information available yet on larval stage, nymph stage, adult stage.
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No information currently available on number and size of offspring and sex ratio of offspring.
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Tayshenata species live sedentary lives living mainly in webs for their whole life except for males who may sometimes leave upon maturity. They do not disperse far as they are known only from two caves. [3]
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Due to the difficulty of viewing the species and their rarity the exact diet of the Government Canyon Bat Cave Spider is not known. However, it is believed that Taysheneta microps feed on the eggs, larvae, or other adult invertebrates living in the cave. [4]
As we have been unable to view many individuals in the Government Canyon Bat Cave species it has been challenging and rare to view their behavior. This is believed to be due to the species dwelling inside portions of the karst cave that are inaccessible to humans. [5] What we do know from the few observed Government Canyon Bat Cave spiders and closely related species is the kind of webs they form and some base behavior. Taysheneta microps has been observed forming small sheet webs under material breakdown, decomposing biomass i.e. guano, and is thought to be mostly sedentary living in their webs their whole life [3]
Tayshenata microps lives in karst limestone caves and are an obligate species. The spiders can no longer have the ability to live in a drier environment so they have to live in the conditions the caves provide. These caves are high in humidity and maintain stable temperatures. The spiders will retreat to a deeper, more habitable portion of the cave in extreme conditions outside the cave. [5]
Taysheneta microps live two caves within Bexar County, Texas. The names of the caves are Government Canyon Bat Cave and Surprise Sink. The spiders may have been found in a third cave, the Madia cave, but the species identity was never confirmed. If these unidentified spiders were classified as Tayshenata microps, then the occupation range would extend to include the Helotes Karst cave region. Currently, the species has a range less than 100 km and global abundance has yet to be determined. [3] [5]
Population size estimates are currently unknown due to limited individuals and inaccessible cave locations. [6] About ninety percent of caves in Bexar County are sealed from human entrance, preventing further research on Tayshaneta microps. [5] Studies suggest that troglobites are neither rare nor associated with the stability issues of small populations. [5] However, due to both the lack of information and access regarding Bexar County invertebrates, such concerns cannot be ruled out.
Tayshaneta microps are known to live in two caves in the Government Canyon State Natural Area, Northern Bexar County, Texas. [6] While the two individuals obtained from Surprise Sink share the reduced eyes of Tayshaneta microps, they have not yet been confirmed as members of the species. [3] Lack of confirmation is due to immaturity and an absence of associated males. [3] Despite numerous sampling efforts, no additional prior or current habitats have been identified [3]
The most widespread threats to Tayshaneta microps are urbanization, population growth and habitat loss. [5] Such factors are amplified by the rapidly expanding city, San Antonio, in Bexar County, Texas. [7] The growth of San Antonio, accompanied by its anthropogenic impacts, has posed many challenges for the species. For example, the karst topography occupied by Tayshaneta microps consists of brittle, limestone caves abundant with sinks, fractures, and fissures. [7] Such environments remain vulnerable to slight movements, often induced by humans. Direct habitat loss often arrives in the form of rock quarrying and filling in cave entrances. [5] These actions prompt the loss of permeability and movement routes for invertebrates. The following are examples of indirect habitat degradation: changing draining paths, displacing native plant and animal species, pollution from septic networks and run-off, and predation or competition via invasive species. [5]
Fire ants present the most plausible nonnative threat to Tayshaneta microps. [5] Despite no observations of the species being preyed upon, a negative correlation does exist between arthropod diversity and fire ant presence. [5] Closely related arthropods in Travis and Williamson Counties, Texas, have been observed to fall prey to fire ants. [5] Such evidence leads experts to believe that Bexar County invertebrates are similarly affected by fire ant competition and predation. Additionally, researchers suspect that Tayshaneta microps may exist in adjacent caves on privately owned land. [7] Due to the regulations associated with land ownership, the preservation of potential arthropod habitats is dependent on consultations with landowners [7]
The United States Fish and Wildlife Service (USFWS) received a petition on January 16, 1992, to add Neoleptoneta microps to the List of Threatened and Endangered Wildlife. [5] This petition included eight additional invertebrates of Bexar County. Dated January 9, 1992, the petition was submitted by the following groups: Patricia K. Cunningham of the Helotes Creek Association, the Balcones Canyonlands Conservation Coalition, the Texas Speleological Association, the Alamo Group of the Sierra Club, and the Texas Cave Management Association. [5] All nine invertebrates were listed as endangered by the USFWS on December 26, 2000. [5]
The USFWS began a 5-year status review of Neoleptoneta microps in 2021. [8] Their endangered status has been maintained, receiving no further updates. [8] After the Neoleptoneta genus was altered to include only seven species of central Mexico, the USFWS updated their taxonomic classification to Tayshaneta microps on November 26, 2021 [8]
A species status assessment for Tayshaneta microps is not available at this time. [6]
The USFWS drafted a recovery plan for endangered karst invertebrates on September 12, 2011. The draft was later finalized on October 4, 2011. [8] Conservation biologists developed many recommendations based on “karst faunal regions” (KFR's). KFRs are classified as distinct, protected cave areas to assist in the recovery of endangered karst invertebrates. [7] In order to ensure a high probability of Tayshaneta microps’ long-term survival, biologists advocate for the protection of an “adequate quantity and quality” (90% chance of species survival over 100 years) of karst areas. [8] The maintenance of KFRs calls for the elimination of the following: extensive human visitation, native plant and animal disturbance, invasive fire ants, and pollution. [8] Additionally, the USFWS recommends the use of adaptive management actions to control both current and new threats. Due to limited information, recovery is also dependent on further research to establish new areas of Tayshaneta microps presence. [8] Such research will work in tandem with outreach efforts to educate the public about endangered karst invertebrates. The USFWS estimates a timeframe of 20 years to accomplish the delisting of Tayshaneta microps if its recovery actions are sufficiently funded and implemented [8]
The Tooth Cave spider, formerly Neoleptoneta myopica, now Tayshaneta myopica, is a 1.6 mm long spider in the family Leptonetidae. It is endemic to limestone caves near Austin, Texas in the United States and is considered an endangered species.
Leptonetidae is a family of small spiders adapted to live in dark and moist places such as caves. The family is relatively primitive having diverged around the Middle Jurassic period. They were first described by Eugène Simon in 1890.
Troglofauna are small cave-dwelling animals that have adapted to their dark surroundings. Troglofauna and stygofauna are the two types of subterranean fauna. Both are associated with subterranean environments – troglofauna are associated with caves and spaces above the water table and stygofauna with water. Troglofaunal species include spiders, insects, myriapods and others. Some troglofauna live permanently underground and cannot survive outside the cave environment. Troglofauna adaptations and characteristics include a heightened sense of hearing, touch and smell. Loss of under-used senses is apparent in the lack of pigmentation as well as eyesight in most troglofauna. Troglofauna insects may exhibit a lack of wings and longer appendages.
The Haplogynae or haplogynes are one of the two main groups into which araneomorph spiders have traditionally been divided, the other being the Entelegynae. Morphological phylogenetic studies suggested that the Haplogynae formed a clade; more recent molecular phylogenetic studies refute this, although many of the ecribellate haplogynes do appear to form a clade, Synspermiata.
Assiminea pecos is a rare species of snail in the family Assimineidae known by the common name Pecos assiminea. It is native to New Mexico and Texas in the United States. Specimens known from Mexico are now treated as members of a separate species, Assiminea cienegensis. The Pecos assiminea was federally listed as an endangered species of the United States in 2005.
Lirceus usdagalun is a rare species of crustacean known by the common name Lee County cave isopod. It is endemic to Virginia in the United States, where it is known from a single network of karst cave systems in Lee County. It is threatened by a number of processes. It is a federally listed endangered species of the United States, and is assessed as "endangered" by the International Union for Conservation of Nature.
The Kretschmarr Cave mold beetle is a small mold beetle.
First opened to the public in October, 2005, Government Canyon State Natural Area (GCSNA) preserves 12,244 acres of rugged hills and canyons typical of the Texas Hill Country. It is designated a Natural Area, rather than a State Park, and therefore the primary focus is maintenance and protection of the property's natural state. Accordingly, access and recreational activities may be restricted if the Texas Parks & Wildlife Department (TPWD) deems such action necessary to protect the environment.
The Modoc sucker is a rare species of freshwater fish native to northern California and southern Oregon. It grows to a length of about 7 in (18 cm) and becomes sexually mature at 4 in (10 cm). It feeds on algae, small invertebrates and detritus, and hides under stones, detritus and overhanging vegetation. It is found in only a few streams and is listed as an endangered species in California and the United States. Conservation measures have been put in place such as fencing the streams in which it lives from livestock. It was previously rated as "endangered" by the International Union for Conservation of Nature, but this rating has now been changed to "near threatened".
The Tooth Cave ground beetle, Rhadine persephone, is an endemic beetle that lives only in karst caves in Texas. These arthropods belong to the family Carabidae. The United States government considers these beetles endangered because they are only found in a single cave system. If these caves are destroyed, this beetle will likely go extinct. The cave system is currently threatened by pollution, urban development, and invasion by fire ants.
Texella reyesi is a rare species of arachnid known by the common name Bone Cave harvestman. It is endemic to Texas in the United States, where it lives in limestone caves in Travis and Williamson Counties. It is threatened by the loss of its habitat. It is a federally listed endangered species of the United States.
The Cokendolpher cave harvestman, Texella cokendolpheri, is a species of cave-living harvestman native to Bexar County, Texas. The original common name, the Robber Baron Cave harvestman, stemmed from the cave which the harvestman inhabits. The scientific name and the current common name honor the prominent arachnologist, James Cokendolpher, who identified the species. T. cokendolpheri is one of twenty-eight species within the North American harvestman genus Texella. The first formal description of the harvestman took place in 1992 and the species’ listing under the Endangered Species Act followed eight years later. Current threats to the species include habitat loss and interactions with invasive fire ants.
Cicurina vespera is a rare species of spider in the family Dictynidae known by the common name Government Canyon Bat Cave meshweaver. It is endemic to Texas in the United States, where it is known from only one cave in Bexar County. This is one of nine invertebrates endemic to the karst caves of Bexar County that were federally listed as endangered species in the year 2000.
Cicurina madla is a rare species of spider in the family Dictynidae known by the common name Madla Cave meshweaver. It is endemic to Texas, United States, where it is known to originate from only eight or nine caves in Bexar County. This is one of a small number of invertebrates endemic to the karst caves of Bexar County that were federally listed as endangered species in the year 2000. Another spider from the caves was described as Cicurina venii, and given the common name Braken Bat Cave meshweaver. In 2018, it was synonymized with C. madla.
Cicurina baronia is a rare species of spider in the family Hahniidae known by the common name Robber Baron cave meshweaver. The species is endemic to the San Antonio, Texas area of the United States. It is one of nine species deemed the Bexar County Invertebrates, as all nine are found in similar cave environments in the central region of Texas. These species range in size from one millimetre to one centimetre. They are also eyeless or essentially eyeless and pale in coloration.
Trogloraptor is a genus of large spiders found in the caves of southwestern Oregon. It is the sole genus in the family Trogloraptoridae, and includes only one species, Trogloraptor marchingtoni. These spiders are predominantly yellow-brown in color with a maximum leg span of 3 in (7.6 cm). They are remarkable for having hook-like claws on the raptorial last segments of their legs.
Tayshaneta is a genus of North American leptonetids that was first described by J. Ledford in 2011.
Rhadine infernalis is a species of troglobitic beetle of the family Carabidae. They are endemic to the county of Bexar, Texas. Within this county, R. infernalis has been found in 39 caves. There are 2 named subspecies of R. infernalis: R. infernalis infernalis and R. infernalis ewersi. There is a third possible subspecies that has not been officially described. R. infernalis was classified in 2000 as endangered under the IUCN Endangered Species Act of 1973, along with 8 other karst invertebrates in the same region. It has the widest known range of the endangered karst invertebrates.
The Tooth Cave pseudoscorpion(Tartarocreagris texana) is a small cave-dwelling arachnid of the family Neobisiidae. The species was originally assigned to the genus Microcreagris, and then reassigned to Austalillocregris before arriving at its current genus, Tartarocreagris. The Tooth Cave pseudoscorpion has a small geographic distribution, known to occur in only two caves in Travis County, Texas. Additionally, it is tentatively identified in two nearby caves in Texas, but more research is necessary to accurately define the range where the species lives. There is little known about the biology, life cycle, and life history of the Tooth Cave pseudoscorpion due to a lack of research and study. Because of this, the Tooth Cave pseudoscorpion is listed on the IUCN Red List as data deficient. Under the Endangered Species Act, the Tooth Cave pseudoscorpion is listed as endangered. Recovery plans for the species focus mostly on preserving the karst ecosystem that the pseudoscorpions live in, especially including lessening human impacts on the environment.
Batrisodes venyivi, also known as Helotes mold beetle, is an eyeless beetle in the family Staphylinidae. They are found exclusively in the dark zones of caves in the Southwest region of Texas. More specifically, they have been found in eight caves throughout Bexar County, Texas. Similar species include the eight other Bexar County invertebrates, such as Rhadine exilis or Rhadine infernalis. All nine of these species are protected under the Endangered Species Act. Despite the efforts of a small number of researchers, the logistical challenges of accessing this habitat greatly limit the amount and type of information. Very little is known of the species' behavior, population trends, or general ecology.