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Cave Biology Data Portal
Subterranean biodiversity of North America and around the globe
AnimaliaArthropodaCrustaceaMalacostracaIsopodaAsellidaeCaecidotea

Nickajack Cave Isopod
Caecidotea nickajackensis Packard, 1881

Taxonomy

Kingdom Animalia
Phylum Arthropoda
Subphylum Crustacea
Class Malacostraca
Order Isopoda
Family Asellidae
Genus Caecidotea
Species Caecidotea nickajackensis Packard, 1881

Synonyms

  • Conasellus nickajackensis (Packard, 1881) (prior combination, CoL)

Description

Diagnostic characters

Ecological class
Stygobiont
Realm
Aquatic
Troglomorphy
Troglomorphic

Distribution

Type locality

Nickajack Cave, Marion Co. TN

Range

Known from 11 counties across seven states in the Interior Low Plateau karst region.

Continent

North America

Country

United States

States and provinces

Alabama, Arkansas, Georgia, Kentucky, Missouri, Tennessee, Virginia

Counties

Alabama
Jackson
Arkansas
Benton
Georgia
Dade, Thomas
Kentucky
Barren, Hart
Missouri
Phelps
Tennessee
Hamilton, Marion
Virginia
Scott, Tazewell

Karst regions

Interior Low Plateau

Specimens

Collections holding material

InstitutionLots
Field Museum of Natural History 4
National Museum of Natural History, Smithsonian Institution 4
Museum of Comparative Zoology, Harvard 1

9 cataloged lots in 3 collections. Compiled from GBIF and not an exhaustive census: many collections are not yet digitised, and holdings are added continually. Search GBIF for specimen records.

Download all 9 specimen records (CSV) Institution, catalog number, type status and preparation. No coordinates.

Conservation and management

IUCN Red List

VU Vulnerable D2

EXEWCRENVU▲NTLC

Assessed in 1996.

NatureServe

G1 Critically Imperiled

G1▲G2G3G4G5

Global rank last reviewed 19 October 2021.

Subnational ranks

Alabama
SNR Unranked
Georgia
SNR Unranked
Tennessee
S1 Critically Imperiled
Virginia
S1 Critically Imperiled

Ranks looked up 23 August 2026. Conservation status changes, and a rank here is as current as that date and no more.

State and federal status

Not listed under the U.S. Endangered Species Act.

Other resources

Catalogue of Life
P7QK
GBIF
2205839
ITIS
92751
iNaturalist
96397

References

  • Banta, A.M. 1907. The fauna of Mayfield's Cave. Carnegie Institution of Washington Publication 67: 1–114. https://www.biodiversitylibrary.org/item/60987. details
  • Coleman, W.T. & Zigler, K.S. 2015. The rediscovery of Caecidotea nickajackensis in Tennessee and Alabama. Speleolobiology Notes 7: 10–13.
  • Cooper, J.E. 1968a. The salamander Gyrinophilus palleucus in Georgia, with notes on Alabama and Tennessee population. Journal of the Alabama Academy of Science 39: 182–185. https://www.biodiversitylibrary.org/page/54954393. details
  • Cope, E.D. & Packard, A.S. 1881. The fauna of the Nickajack Cave. American Naturalist 15: 877–882.
  • Engel, A.S. & Niemiller, M.L. 2024. The Southern Cumberland Plateau. In: Weaver, A. (ed), 2024 NSS Convention Guidebook: TAG Tour 2024, pp. 24–30. National Speleological Society, Huntsville, Alabama, USA.
  • Hay, W.P. 1901. Two new subterranean crustaceans from the United States. Proceedings of the Biological Society of Washington 14: 179–180. https://www.biodiversitylibrary.org/page/2339123. details
  • Hay, W.P. 1902a. Observations on the crustacean fauna of Nickajack Cave, Tennessee, and vicinity. Proceedings of the United States National Museum 25: 417–439. doi:10.5479/si.00963801.25-1292.417
  • Lewis, J.J. 1988. The systematics, zoogeography and life history of the troglobitic isopods of the Interior Plateaus of the eastern United States. University of Louisville, Louisville, Kentucky, USA. 281 pp.
  • Lewis, J.J. 2005a. A biological inventory of caves of the Cumberland Plateau. Tennessee Chapter Cave Program, The Nature Conservancy, Nashville, Tennessee, USA. 156 pp.
  • Lewis, J.J. 2009a. On the identity of Caecidotea nickajackensis (Crustacea: Isopoda: Asellidae). Proceedings of the Biological Society of Washington 122: 215–224. doi:10.2988/08-47.1
  • Lewis, S.L., Lewis, J.J. & Orndorff, W. 2021. Caecidotea burkensis, new species, a unique subterranean isopod from Burke’s Garden, with a synthesis of the biogeography and evolution of southwestern Virginia asellids. Journal of Cave and Karst Studies 83: 78–87. doi:10.4311/2020LSC0126
  • Nicholas, G. 1960. Checklist of macroscopic troglobitic organisms of the United States. The American Midland Naturalist 64: 123–160. doi:10.2307/2422897
  • Niemiller, M.L. & Zigler, K.S. 2013. Patterns of cave biodiversity and endemism in the Appalachians and Interior Plateau of Tennessee, USA. PLOS One 8: e64177. doi:10.1371/journal.pone.0064177
  • Steeves, H.R. 1964. The troglobitic asellids of the United States: the hobbsi group. The American Midland Naturalist 71: 445–451. doi:10.2307/2423303
  • Steeves, H.R. 1966. Evolutionary aspects of the troglobitic asellids of the United States: the hobbsi, stygius and cannulus groups. The American Midland Naturalist 75: 392–403. doi:10.2307/2423400
  • Zigler, K.S., Niemiller, M.L., Stephen, C.D.R., Ayala, B.N., Milne, M.A., Gladstone, N.S., Engel, A.S., Jensen, J.B., Camp, C.D., Ozier, J.C. & Cressler, A. 2020. Biodiversity from caves and other subterranean habitats of Georgia, USA. Journal of Cave and Karst Studies 82: 125–167. doi:10.4311/2019LSC0125

This account was last revised 28 August 2026. Conservation ranks were looked up 23 August 2026.

How to cite this account

Caecidotea nickajackensis Packard, 1881. Cave Biology Data Portal, account SP-1232. https://cavebiology.org/species/caecidotea-nickajackensis/ (accessed 18 October 2026).
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Data sources and funding are listed in the Acknowledgments.

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Cave Biology Data Portal

Species accounts, distributions, and conservation status for the subterranean fauna of North America and around the globe, with resources for the cave and karst research community.

Text and data CC BY 4.0. Images all rights reserved unless stated.

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