Kauaʻi cave wolf spider

{{Short description|Species of spider}} {{Speciesbox | name = Kauaʻi cave wolf spider | image = Adelocosa anops.jpg | status = EN | status_system = IUCN2.3 | status_ref = <ref name="iucn status 20 November 2021">{{cite iucn |author=World Conservation Monitoring Centre |date=1996 |title=''Adelocosa anops'' |volume=1996 |article-number=e.T513A13058776 |doi=10.2305/IUCN.UK.1996.RLTS.T513A13058776.en |access-date=20 November 2021}}</ref> | parent_authority = [[Willis J. Gertsch|Gertsch]], 1973 | taxon = Adelocosa anops | authority = Gertsch, 1973<ref>{{cite web |author=Norman I. Platnick |author-link=Norman I. Platnick |year=2010 |url=http://www.wsc.nmbe.ch/resources/archive/catalog_10.5/LYCOSIDAE.html |title=Lycosidae |work=[[World Spider Catalog]], Version 10.5 |publisher=[[American Museum of Natural History]] |access-date=March 17, 2010}}</ref> | range_map = Distribution.adelocosa.anops.1.png }}

The '''Kaua{{okina}}i cave wolf spider''' ('''''Adelocosa anops'''''), also known to local residents as the '''blind spider''', is a species of [[wolf spider]]. It is [[monotypic]] within the genus ''Adelocosa''.

The Kaua{{okina}}i cave wolf spider is only known to occur in a few [[cave]]s in a [[lava flow]] with an area of {{convert|10.5|km2|abbr=on}} in the [[Koloa, Hawaii|Kōloa]]–[[Poipu, Hawaii|Po{{okina}}ipū]] region of [[Kauai|Kaua{{okina}}i]], [[Hawaiian Islands]], and only six populations are known to exist.<ref name="FWS">{{cite web |date=January 6, 2010 |title=Endangered Species in the Pacific Islands. Kaua'i Cave Arthropods |url=http://www.fws.gov/pacificislands/fauna/kauaicaveanimals.html |publisher=[[United States Fish and Wildlife Service]] |access-date=March 18, 2010 |archive-date=July 31, 2010 |archive-url=https://web.archive.org/web/20100731035916/http://www.fws.gov/pacificislands/fauna/kauaicaveanimals.html }}</ref> While their nearest surface-dwelling relatives have large eyes, this species has completely lost its eyes. They reach a body length around {{convert|20|mm|1|abbr=on}}, and are reddish brown and completely harmless to people.<ref name="HI" /> Unlike most wolf spiders, it produces only 15 to 30 eggs per clutch. The female carries the egg sac in her mouthparts until the spiderlings hatch.<ref name="FWS" />

One of its primary prey species is the Kauaʻi cave amphipod, ''[[Spelaeorchestia koloana]]'', which is only known from nine populations and reaches about {{convert|10|mm|1|abbr=on}} in length.<ref name="HI" /> These feed on decomposing plant matter. The Kauaʻi cave wolf spider was discovered in 1973.<ref name="FWS2">{{cite web |date=July 21, 2014 |title=Shining a Light on Kauai's Buried Treasure |url=https://www.fws.gov/endangered/news/episodes/bu-Spring-Summer2014/story3/ |publisher=[[United States Fish and Wildlife Service]]}}</ref> Counts have never documented more than 30 spiders or 80 amphipods.<ref name="HI">{{cite web |date=October 1, 2005 |title=Hawaii's Comprehensive Wildlife Conservation Strategy (2005): Kaua'i Cave Arthropods |url=http://www.state.hi.us/dlnr/dofaw/cwcs/files/NAAT%20final%20CWCS/Chapters/Terrestrial%20Fact%20Sheets/Inverts/Kauai%20Cave%20arthropods%20NAAT%20final%20!.pdf |archive-url=https://web.archive.org/web/20070317000559/http://www.state.hi.us/dlnr/dofaw/cwcs/files/NAAT%20final%20CWCS/Chapters/Terrestrial%20Fact%20Sheets/Inverts/Kauai%20Cave%20arthropods%20NAAT%20final%20!.pdf |archive-date=March 17, 2007 |access-date=August 6, 2006}}</ref>

== Description == Adult Kauaʻi cave wolf spiders typically measure between 12.7 and 19.0 millimeters (0.5-0.75 inches) in length.<ref name=":0">{{Cite web |title=ECOS: Species Profile |url=https://ecos.fws.gov/ecp/species/7122 |access-date=2022-04-26 |website=ecos.fws.gov}}</ref> The Kauaʻi cave wolf spider is the only wolf spider to completely lack eyes.<ref name=":1">{{Cite journal |last=Gertsch |first=Willis J. |date=20 May 1973 |title=The Cavernicolous Fauna of Hawaiian Lava Tubes, 3. Araneae (Spiders) |url=http://hbs.bishopmuseum.org/pi/pdf/15(1)-163.pdf |journal=Pacific Insects |volume=15 |issue=1 |pages=163–180}}</ref> It has a reddish brown to orange [[carapace]] with a pale abdomen and bright orange legs.<ref name=":1" /> Each leg has four pairs of short black spines and a thin coating of pale, silky hairs.<ref name=":1" /> The [[Chelicerae|chelicera]] has three large teeth used for biting prey.<ref name=":0" />

== Life history == Kauaʻi cave wolf spiders have a small clutch size compared to other wolf spiders. Kauaʻi cave wolf spiders only produce 15-30 eggs per clutch, whereas other terrestrial wolf spiders may have 100 to 300. Female Kauaʻi cave wolf spiders carry their egg sacs on their backs until their spiderlings hatch in 30 to 50 days. Upon hatching, the large spiderlings are carried on the back of the mother for several days. Kauaʻi cave wolf spiders have an adapted row of comb-like teeth on their claws. These align with the branched hairs of their mother's back and allow the spiderlings to hold onto the mother securely for protection and transport.<ref name=":2" /> This species takes up to a year to reach sexual maturity. At that time, the spiderlings are old enough to hunt for themselves and disperse from the mother.<ref name=":0" />

Little is known about the mating strategies of Kauaʻi cave wolf spiders.

Ecologists hypothesize that Kauaʻi cave wolf spider life history has been shaped by a behavior that allows other wolf spiders to fly through the air at short and long distances. Aerial dispersal is a behavior employed most often by young spiderlings, or [[instar]]s, though it has never been observed in Kauaʻi cave wolf spiders.<ref name=":4">{{Cite journal |last1=Carlozzi |first1=Ana |last2=Bidegaray-Batista |first2=Leticia |last3=González-Bergonzoni |first3=Ivan |last4=Aisenberg |first4=Anita |date=2018 |title=Flying sand-dwelling spiders: aerial dispersal in Allocosa marindia and Allocosa senex (Araneae: Lycosidae) |journal=Journal of Arachnology |volume=46 |pages=7–12 |doi=10.1636/JoA-S-17-026.1 |s2cid=90751319 |language=English |issn=0161-8202}}</ref> However, there are close relatives to this species that are able to aerially disperse that inhabit the islands next to Kauaʻi. This suggests that Kauaʻi cave wolf spiders originated from an ancestor that came from other nearby Hawaiian islands.<ref name=":1" /> Dispersal mechanisms and behaviors allow individuals in a population to avoid competition for resources, unfavorable environmental conditions, and predation. Utilizing aerial dispersal would be dependent on the trade-off between the costs of landing in an unstable environment and the benefits of finding a new environment with fewer constraints or threats.<ref name=":4" />

== Ecology ==

=== Diet === The Kauaʻi cave wolf spider is an opportunistic feeder, meaning it feeds on other cave inhabitants whenever possible. Its diet may include the Kaua'i cave amphipod, as well as introduced spiders and cockroaches.<ref name=":2">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.</ref>

=== Behavior === The Kauaʻi cave wolf spider is slow-moving and spends most of its time standing still.<ref name=":2" /> Instead of building a web, the Kauaʻi cave wolf spider waits on the ground for prey.<ref name=":3">{{Cite journal |last=Howarth |first=F G |date=1983-01-01 |title=Ecology of Cave Arthropods |url=https://www.annualreviews.org/doi/10.1146/annurev.en.28.010183.002053 |journal=Annual Review of Entomology |volume=28 |issue=1 |pages=365–389 |doi=10.1146/annurev.en.28.010183.002053 |issn=0066-4170|url-access=subscription }}</ref> It senses prey through vibrations and chemical signals.<ref name=":3" /> Once it senses prey, the spider approaches and alternates raising its front legs vertically.<ref name=":3" /> Little information is available about the spider's mating behavior, but it is known that females carry the egg sac and care for the young.<ref>{{Cite journal |last=Howarth |first=Francis G. |date=1987-07-01 |title=Evolutionary ecology of aeolian and subterranean habitats in Hawaii |journal=Trends in Ecology & Evolution |language=en |volume=2 |issue=7 |pages=220–223 |doi=10.1016/0169-5347(87)90025-5 |pmid=21227855 |bibcode=1987TEcoE...2..220H |issn=0169-5347}}</ref>

=== Habitat === The Kauaʻi cave wolf spider is an obligate cave-dweller. It lives in large cave passages, small [[wiktionary:mesocavern#English|mesocaverns]], and cracks that are inaccessible to humans. Since they can die of [[desiccation]] in low humidity, the Kauaʻi cave wolf spider requires a high humidity habitat. Because of this, they prefer to inhabit the dark and stagnant air zones of caves. These zones are characterized by high humidity, low air movement, and low temperature fluctuations.<ref name=":2" />

=== Range === The Kauaʻi cave wolf spider is only found in the [[Koloa, Hawaii|Koloa]] Basin of the Hawaiian island of [[Kauai|Kauaʻi]]. Within the island, Kauaʻi cave wolf spiders are only found in three caves regularly. These are called Koloa Cave 1, Koloa Cave 2, and [[Kiahuna Mauka Cave]]. Kauaʻi cave wolf spiders are also found in one experimental cave operated by the [[United States Fish and Wildlife Service|US Fish and Wildlife Service]], called Cave 3075C.<ref name=":0" />

== Conservation == The Kauaʻi cave wolf spider was first listed as endangered under the [[Endangered Species Act of 1973|Endangered Species Act]] in 2000, after being proposed to be listed in 1997.<ref>{{Cite journal |last=Hopper |first=David |date=January 14, 2000 |title=Endangered and Threatened Wildlife and Plants; Final Rule To List Two Cave Animals From Kauai, Hawaii, as Endangered |url=https://www.govinfo.gov/content/pkg/FR-2000-01-14/pdf/00-982.pdf |journal=Federal Register |volume=65 |issue=10 |pages=2348–2357}}</ref> Three 5-year reviews have been filed mentioning the Kauaʻi cave wolf spider in 2005,<ref>{{Cite journal |date=July 6, 2005 |title=Endangered and Threatened Wildlifeand Plants; Initiation of 5-Year Reviews of the Mariana Fruit Bat (Pteropus mariannus mariannus), Mariana Crow (Corvus hawaiiensis), Laysan Duck (Anas laysanensis), Kauai Akialoa (Honeycreeper)(Hemignathus procerus), Large Kauai Thrush (Myadestes myadestinus), Kauai Oo (Honeyeater) (Moho braccatus), Ou (Honeycreeper) (Psittirostra psittace), Molokai Creeper (Paroreomyza flammea), Molokai Thrush (Myadestes lanaiensis rutha), Kauai Cave Wolf Spider (Adelocosa anops) Kauai Cave Amphipod (Spelaeorchestia koloana), Alsinidendron obovatum (No Common Name), Amaranthus brownii (No Common Name), Chamaesyce celastroides var. kaenana (Akoko), Chamaesyce deppeana (Akoko), Chamaesyce herbstii (Akoko), Chamaesyce skottsbergii var. kalaeloana (Ewa Plains Akoko),Clermontia pyrularia (Oha Wai), Cyanea grimesiana ssp. obatae (No Common Name), Cyanea pinnatifida (Haha), Cyanea st.-johnii (Haha), Cyanea superba (Haha), Cyanea truncata (Haha), Cyrtandra dentate (Haiwale), Gouania vitifolia (No Common Name), Hedyotis degeneri (No Common Name), Hibiscadelphus woodii (Hau Kuahiwi), Castilleja levisecta (Golden paintbrush), Fender's Blue Butterfly (Icaricia icarioides fenderi), Erigeron decumbens var. decumbens (Willamette Daisy), Lupinus sulphureus ssp. kincaidii (Kincaid's Lupine), Lomatium bradshawii (Bradshaw's Desert Parsley), and Sidalcea nelsoniana (Nelson's Checker-mallow) |url=https://www.federalregister.gov/documents/2005/07/06/05-13219/endangered-and-threatened-wildlife-and-plants-initiation-of-5-year-reviews-of-the-mariana-fruit-bat |journal=Federal Register |volume=70 |issue=128 |pages=38972–38975 |via=National Archives}}</ref> 2015,<ref>{{Cite journal |date=February 13, 2015 |title=Endangered and Threatened Wildlife and Plants; Initiation of 5-Year Status Reviews of 133 Species in Hawaii, Oregon, Idaho, and Washington |url=https://www.federalregister.gov/documents/2015/02/13/2015-03015/endangered-and-threatened-wildlife-and-plants-initiation-of-5-year-status-reviews-of-133-species-in |journal=Federal Register |volume=80 |issue=30 |pages=8100–8103 |via=National Archives}}</ref> and 2020<ref>{{Cite journal |date=March 11, 2020 |title=Endangered and Threatened Wildlife and Plants; Initiation of 5-Year Status Reviews for 129 Species in Oregon, Washington, Idaho, Hawaii, Montana, California, and Nevada |url=https://www.federalregister.gov/documents/2020/03/11/2020-04942/endangered-and-threatened-wildlife-and-plants-initiation-of-5-year-status-reviews-for-129-species-in |journal=Federal Register |volume=85 |issue=48 |pages=14240–14243 |via=National Archives}}</ref> which have considered the spider to still be endangered.

=== Threats === The Kauaʻi cave wolf spider is threatened by habitat modification, novel competition, and chemical runoff. Habitat modification is largely due to human development and interaction.<ref name=":2" /> Construction projects can expose caves to surface air and [[Desiccation|desiccate]] the subterranean environment. This also allows novel species like the introduced [[brown violin spider]] to enter, which is known to outcompete with the native Kauaʻi cave wolf spider for prey. Development of agriculture and recreational areas, for example golf courses, change the surface vegetation composition above cave environments. This vegetation's shallow root composition decreases input of detritus into cave systems and increases sediment deposition. Recreational exploration of caves by humans also negatively impacts the delicate ecosystem of the cave as well.<ref name=":2" />

=== Recovery === A recovery plan published in 2006 stated that the Kauaʻi cave wolf spider would be delisted as endangered when 12 populations of the spider are observed to have the following conditions: stable, self-sustaining, protected from human interference, and its habitat being utilized in a manner conducive to conservation.<ref name=":2" />

Recovery actions to meet this goal include protecting known populations from human-induced degradation, enhancing habitats known previously to have populations, conducting research to identify species-specific conservation strategies, educating the public on conservation efforts, and validating current conservation practices.<ref name=":2" />

== See also ==

* [[List of troglobites]]

== References == {{Reflist|2}}

{{DEFAULTSORT:Kaua'i cave wolf spider}} [[Category:Lycosidae]] [[Category:Cave spiders]] [[Category:Spiders of Hawaii]] [[Category:Biota of Kauai]] [[Category:Endemic fauna of Hawaii]] [[Category:Endangered fauna of Hawaii]] [[Category:ESA endangered species]] [[Category: Blind animals]] [[Category:Taxa named by Willis J. Gertsch]]