Two-toothed Cave Isopod
Caecidotea bicrenata (Steeves, 1963)

Taxonomy

Synonyms

Description

Diagnostic characters

Ecological class

Stygobiont

Realm

Aquatic

Troglomorphy

Troglomorphic

Distribution

Type locality

Guffey Cave, Marshall Co, AL

Range

Known from 59 counties across four states across two karst regions.

Continent

North America

Country

United States

States and provinces

Alabama, Illinois, Kentucky, Tennessee

Counties

Alabama

Colbert, Jackson, Lauderdale, Limestone, Madison, Marshall, Morgan

Illinois

Johnson, Massac, Union

Kentucky

Barren, Caldwell, Christian, Crittenden, Edmonson, Hart, Livingston, Logan, Metcalfe, Monroe, Simpson, Todd, Trigg, Warren

Tennessee

Bedford, Cannon, Clay, Coffee, Davidson, DeKalb, Decatur, Dickson, Franklin, Giles, Grundy, Hardin, Hickman, Jackson, Lawrence, Lewis, Macon, Marion, Marshall, Maury, Montgomery, Moore, Overton, Perry, Putnam, Robertson, Rutherford, Smith, Stewart, Sumner, Van Buren, Warren, Wayne, White, Wilson

Karst regions

Interior Low Plateau, Ozarks

Genetics

Molecular resources

28 sequences, retrieved 23 August 2026. Counts change as sequences are deposited. Search GenBank.

Download all 28 sequence records (CSV) Accession, marker, molecule type, length, GenBank definition and a direct link.

Specimens

Type material

Holotype

USNM 172775 · National Museum of Natural History, Smithsonian Institution

Holotype

USNM 172791 · National Museum of Natural History, Smithsonian Institution

Holotype

USNM 107793 · National Museum of Natural History, Smithsonian Institution

Allotype

USNM 107794 · National Museum of Natural History, Smithsonian Institution

Paratype ×11

National Museum of Natural History, Smithsonian Institution

Collections holding material

66 cataloged lots in 2 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 66 specimen records (CSV) Institution, catalog number, type status and preparation. No coordinates.

Conservation and management

NatureServe

G5 Secure

Global rank last reviewed 21 August 2002.

Subnational ranks

Alabama

SNR Unranked

Illinois

SNR Unranked

Kentucky

SNR Unranked

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

68TC9

GBIF

2205894

ITIS

92724

iNaturalist

215625

NCBI Taxonomy

1035145

References

• Brandon, R.A. 1967b. Food and an intestinal parasite of the troglobitic salamander Gyrinophilus palleucus necturoides. Herpetologica 23: 52–53.
• Cooper, J.E. & Cooper, M.R. 2011. Observations on the biology of the endangered stygobiotic shrimp Palaemonias alabamae, with notes on P. ganteri (Decapoda: Atyidae). Subterranean Biology 8: 9–20.
• Cooper, J.E. & Kuehne, R.A. 1974. Speoplatyrhinus poulsoni, a new genus and species of subterranean fish from Alabama. Copeia 1974: 486–493.
• Dixon, G.B. & Zigler, K.S. 2011. Cave-obligate biodiversity on the campus of Sewanee: The University of the South, Franklin County, Tennessee. Southeastern Naturalist 10: 251–266. https://www.jstor.org/stable/41263008. details
• Fleming, L.E. 1972. The evolution of the eastern North American isopods of the genus Asellus (Crustacea: Asellidae). Part I. International Journal of Speleology 4: 221–256. https://digitalcommons.usf.edu/cgi/viewcontent.cgi?article=1605&context=ijs. details
• Harker, D.F., Jr. & Barr, T.C., Jr. 1980. Caves and associated fauna of the Western Kentucky coal field, Volume 2. Kentucky Nature Preserves Commission, Frankfurt, Kentucky, USA. 114 pp.
• Hobbs, III., H.H. 1994. Assessment of the ecological resources of the caves of Russell Cave National Monument, Jackson County, Alabama and of selected caves at the Lookout Mountain Unit of Chickamauga-Chattanooga National Military Park, Dade County, Georgia and Hamilton County, Tennessee. 200 pp.
• Hobbs, H.H., Jr. & Barr, T.C., Jr. 1960. The origins and affinities of the troglobitic crayfishes of North America (Decapoda, Astacidae). I. The genus Cambarus. The American Midland Naturalist 64: 12–33. doi:10.2307/2422890
• Holt, P.C. 1963. A new branchiobdellid (Branchiobdellidae: Cambarincola). Journal of the Tennessee Academy of Science 38: 97–100.
• Holt, P.C. 1973. Branchiobdellids (Annelida: Clitellata) from some eastern North American caves, with descriptions of new species of the genus Cambarincola. International Journal of Speleology 5: 219–256.
• Huntsman, B.M., Venarsky, M.P. & Benstead, J.P. 2011b. Relating carrion breakdown rates to ambient resource level and community structure in four cave stream ecosystems. Journal of the North American Benthological Society 30: 882–892. doi:10.1899/10-116.1
• Huntsman, B.M., Venarsky, M.P., Benstead, J.P. & Huryn, A.D. 2011a. Effects of organic matter availability on the life history and production of a top vertebrate predator (Plethodontidae: Gyrinophilus palleucus) in two cave streams. Freshwater Biology 56: 1746–1760.
• Lawson, K.M., Schotz, A.R., Jenkins, A.J., Armbruster, J.W., Black, C., Callahan, M., Goertzen, L., Hansen, C., Stephen, C.D.R., Werneke, D., Mendonca, M. & Molina, E. 2021. Planning level survey of Redstone Arsenal for at-risk species and ecologically significant communities. Environmental Management Division, U.S. Army Garrison, Redstone Arsenal, Huntsville, Alabama, USA. 402 pp.
• Lewis, J.J. 1982b. Systematics of the troglobitic Caecidotea (Crustacea: Isopoda: Asellidae) of the southern Interior Low Plateaus. Brimleyana 8: 65–74. https://www.biodiversitylibrary.org/page/42326177. details
• 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, J.J. & Bowman, T.E. 1981. The subterranean asellids (Caecidotea) of Illinois (Crustacea: Isopoda: Asellidae). Smithsonian Contributions to Zoology 335: 1–66. doi:10.5479/si.00810282.335
• Lewis, J.J. & Lewis, S.L. 2005. Inventory of the subterranean fauna of Tims Ford State Park, Franklin County, Tennessee. Tennesee Natural Heritage Program, Nashville, Tennessee, USA. 28 pp.
• Lewis, J.J. & Lewis, S.L. 2007. A biological reconnaissance of selected caves in the Highland Rim area of central Tennessee. Tennessee Chapter Cave Program, The Nature Conservancy, Nashville, Tennessee, USA. 42 pp.
• Lewis, J.J., Whitaker, J.O. & Krantz, G.W. 2010. A biological reconnaissance of the invertebrate fauna of twelve Tennessee caves with notes on the guanophilic mites of the genus Macrocheles. Journal of the Tennessee Academy of Science 85: 53–61.
• McGregor, S.W., O'Neil, P.E., Rheams, K.F., Moser, P.H. & Blackwood, R. 1997. Biological, geological, and hydrological investigations in Bobcat, Matthews, and Shelta caves and other selected caves in north Alabama. Geological Survey of Alabama Bulletin 166: 1–198.
• McGregor, S.W., Rheams, K.F., O'Neil, P.E., Moser, P.H. & Blackwood, R. 1994. Biological, geological, and hydrological investigations in Bobcat, Matthews, and Shelta caves and other selected caves in north Alabama. Geological Survey of Alabama, Tuscaloosa, Alabama, USA. 226 pp.
• Niemiller, M.L., Anderson, C.L., Maxwell, E.C., Midgette, H., Quering, C., Richards, M., Wilson, K. & Wirwa, N. 2025b. A noteworthy range extension of the federally endangered Alabama Cave Shrimp (Palaemonias alabamae) south of the Tennessee River in northern Alabama. Southeastern Naturalist 24: N47-N58. doi:10.1656/058.024.0403
• Niemiller, M.L., Slay, M.E., Inebnit, T., Miller, B., Tobin, B., Cramphorn, B., Hinkle, A., Jones, B.D., Mann, N. & Niemiller, K.D.K. 2023a. Fern Cave: a hotspot of subterranean biodiversity in the Interior Low Plateau karst region of Alabama in the southeastern United States. Diversity 15: 633. doi:10.3390/d15050633
• 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
• Niemiller, M.L., Zigler, K.S., Hinkle, A., Stephen, C.D.R., Cramphorn, B., Higgs, J., Mann, N., Miller, B.T., Niemiller, K.D.K., Smallwood, K. & Hardy, J. 2023b. The Crystal-Wonder Cave System: a new hotspot of subterranean biodiversity in the southern Cumberland Plateau of south-central Tennessee, USA. Diversity 15: 801. doi:10.3390/d15070801
• Page, G. 2021. Troglofauna of Van Buren and White County: a survey of four caves in the mideastern Cumberland Plateau. The University of Tennessee at Chattanooga, Chattanooga, Tennessee, USA. 18 pp.
• Pearson, W.D. & Boston, C.H., Jr. 1995. Distribution and status of the northern cavefish, Amblyopsis spelaea. Indiana Department of Natural Resources, Division of Fish and Wildlife, Nongame and Endangered Wildlife Program,, Indianapolis, Indiana, USA. 99 pp.
• Poulson, T.L. 1961. Cave adaptation in amblyopsid cavefishes. University of Michigan, Ann Arbor, Michigan, USA. 185 pp. doi:10.7302/9847
• Rheams, K.F., Moser, P.H. & McGregor, S.W. 1992. Geologic, hydrologic, and biologic investigations in Arrowwood, Bobcat, Matthews, and Shelta caves and selected caves, Madison, County, Alabama. Geological Survey of Alabama, Tuscaloosa, Alabama, USA. 262 pp.
• Rheams, K.F., Moser, P.H. & McGregor, S.W. 1994. Hydrogeologic and biologic factors related to the occurrence of the Alabama cave shrimp (Palaemonias alabamae), Madison County, Alabama. Geological Survey of Alabama Bulletin 161: 1–147.
• Simmons, D.D. 1975. The evolutionary ecology of Gyrinophilus palleucus. University of Florida, Gainesville, Florida, USA. 105 pp.
• Steeves, H.R. 1963. The troglobitic asellids of the United States: the stygius group. The American Midland Naturalist 69: 470–481. doi:10.2307/2422923
• Venarsky, M.P., Benstead, J.P. & Huryn, A.D. 2012a. Effects of organic matter and season on leaf litter colonisation and breakdown in cave streams. Freshwater Biology 57: 773–786. doi:10.1111/j.1365-2427.2012.02742.x
• Wakefield, K.R. & Zigler, K.S. 2012. Obligate subterranean fauna of Carter State Natural Area, Franklin County, Tennessee. Speleolobiology Notes 4: 24–28.
• Zigler, K.S. & Cooper, G.M. 2011. Brood size of the stygobiotic asellid isopod Caecidotea bicrenata from Franklin County, Tennessee, USA. Speleolobiology Notes 3: 1–3.

How to cite this account

Data sources and funding are listed in the Acknowledgments.

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