Cottus specus

Adams and Burr in Adams, Burr, Day and Starkey 2013



Cottus carolinae species group  [Burr, Adams, Krejca and Warren 2001]

The common name is Grotto Sculpin (Adams et al. 2013)




Holotype: SIUC 88001 ♂ 80.2mm SL.

Paratypes: SIUC 88002 (2 specimens) 58.0mm SL and 60.6mm SL, USNM 409781 (2 specimens) 65.3mm SL and 86.7mm SL.


Hypogean populations have been found in five large base level caves and six resurgenses in Perry County, Missouri, USA (37o35’N, 90o05’W). These are in two separate karst basins: Mystery-Rimstone Karst (MRK in the Table) to the east of the surface river called Cinque Hommes Creak, and Central Perryville Karst (CPK in the Table) to the west of the river. The extensive Mystery Cave may contain up to 2000 individuals (Burr, Adams, Krejca, Paul and Warren 2001). Troglomorphic individuals have also been collected in epigean waters of eight rivers in the region, presumably after leaving the caves via the resurgences. In the Table below the two letter abbreviations are to assist in interpretation of the Tables and Figures in Day et al. (2014).

Elliott (2007) says of the Perryville karst "Some of the densest known karst development in the USA occurs in Perry County, in limestones of middle Ordovician age or older. About 700 cave entrances are recorded in the large sinkhole plain, with many large river caves, such as Crevice Cave, the longest in Missouri at 45 km. Large stream caves are especially developed in the Cinque Hommes Creek area. The uplands are covered with up to 10 m of loess derived from the Mississippi River flood plain (Vandike, 1985), and there is heavy row crop agriculture. Biologically similar to the Jefferson-Ste. Genevieve Karst, the Perryville Karst has its own endemics and lacks trechine beetles. Endemic species include Sphalloplana evaginata, Perryville cave planarian, Kenkia lewisi, Lewis’ cave planarian, and Cottus [specus] ... Grotto sculpin (Burr et al., 2001), now on Missouri’s Species of Concern List. Mystery Cave ranks as third in cave biodiversity in Missouri. With 18 troglobites, this karst has high area endemism."

  Area Location Type of site
1 CPK Moore Cave TM Cave
2 CPK Crevice Cave (inc. Mertz Cave) CC Cave
3 MRK Mystery Cave * MC Cave
4 MRK Running Bull Cave RB Cave
5 MRK Rimstone River Cave (inc. Hot Caverns) RR Cave
6   Blue Spring BS Resurgence
7   Cinque Hommes Creek CH Resurgence
8   Mystery Resurgence MR Resurgence
9   Thunderhole Resurgence TH Resurgence
10   Greasy Creak GC Resurgence
11   Gerler Spring GS Resurgence
12   Dry Fork Creek DF Surface river
13   Current River CR Surface river
14   Saline Creek SC Surface river
15   Apple Creek AC Surface river
16   Brazeau Creek BZ Surface river
17   Wolf Creek WC Surface river
18   Whitewater River WW Surface river
19   Southfork saline River SF Surface river
    Details from Day et al. (2014)  
    * Type locality  



Grotto Sculpin live in running water in base level streams. They are found in pools and riffles and over a variety of substrates (Burr, Adams, Krejca, Paul and Warren 2001).

Krejca (1994)

Fernholz (2017)

Ferholz (2018)

Chowning (2020)


Rewrite all of this

There are remarkable differences between Grotto Sculpin and surface C. carolinea. They show apparent cave modifications including: reduced pigment, reduced eye size, reduced number of pelvic fin rays, a gap between the dorsal fins, a modified cephalic lateral line system and a longer caudal peduncle. Burr, Warren and Paul (1992), Paul, Burr and Warren (1993) and Burr, Adams, Krejca, Paul and Warren (2001) analysed 10 meristic and 28 morphometric variables in epigean and hypogean specimens. A Principal Component Analysis showed there to be a total separation of the epi- and hypogean populations in eye length vs. standard length, pelvic fin ray number and details of the cephalic lateral line system. It seems possible that this is an example of a troglophile/troglobite transition.

Biological Notes

Through the work of Brooks Burr and his students at Southern Illinois University, beginning in the early 1990s, continued by Ginny Adams and her students at the University of Central Arkansas, and more recently by John Schiebe and his students at Southeast Missouri State University, a considerable amount is known about numerous aspects of the biology of this species. The following is a selection of publications which will provide a well-rounded introduction to what is known.

Peck and Lewis (1977) A comprehensive account of the invertebrates which inhabit the caves containing Cottus specus.

Vandike (1985) Descibes the hydrogeology of the Perriville karst area.

Walsh (1988), Walsh (1989), Walsh (1995) These three sources describe in detail two of the main caves in which Cottus specus is found: Mystery cave and Rimstone River Cave.

Gardner (1986) Describes the invertebrates found in Missouri caves and springs, therefore of direct ecological relevance.

Burr, Warren and Paul (1992), Paul, Burr and Warren (1993), Krejca, Burr, Warren and Paul (1994), Krejca, Burr, Paul and Warren (1994). These four publications were all short abstracts for various conferences and I have not been able to obtain any of them to see what they said.

Paul (1994) A thesis describing aspects of cave adaptation.

Krejca (1994) With Walsh (above) the most important source for the caves in which this species is found.

Burr, Adams, Krejca, Paul and Warren (2001) The first comprehesive account of the biology of Grotto Sculpin which was still, at that time, considered as a member of the species Cottus corolinae. This paper and Adams (2005) are the most significant accounts of the overall biology, though some later publications get into more detail about particular parts of the biology.

Brison (2001) A thesis studying experimental analysis of metabolic adaptation in response to photoperiod and food availability.

Adams (2005) This Ph.D. thesis is equally as important for detail as the Burr et al. (2001) paper and should be consulted by anyone with an interest in this species.

Kinziger, Goodman and Studebaker (2007) Shows that there is a great deal of genetic structure within Cottus carolinae, laying the groundwork for the creation of a new species in 2013.

Elliott (2007) A major review of caves, karst, conservation and biogeography in Missouri.

Gerken and Adams (2008) A short paper on habitat use.

Johnson, Day and Adams (2008) Probably a meeting abstract describing life history characteristics in cave and surface streams.

Adams, Day, Gerken and Johnson (2008) Population ecology.

Day, Johnson, Gerken and Adams (2008) Population ecology.

Fox, Adams, Sharum and Steelman (2010) Passive sampling of bioavailable organic chemicals in cave streams.

USFWS (2013) Species listed as Federally Endangerd by US Fish and Wildlife Sercice.

USFWS (2013) Brief note announcing the Listing.

Crabill, Simmons, Marquardt and Salveter (2013) Describes the actions taken to protect the species once it was listed as Federally Endangered in 2013.

Perry County Community Conservation Plan (2013) Draft plan for water protection in Perry County

Moss (2013) Recharge area delineations and hazard and vulnerability mapping in the Perriville karst

Adams, Burr, Day and Starkey (2013) The long awaited step of creating a new species, Cottus specus, for the Grotto Sculpin.

Crites and Schubert (2013)

Industrial Economics Incorporated (2013) A very intensive and extensive analysis of the financial costs of implementing the Endangered species protection plans.

Day, Starkey, Adams, Brummett and Keeney (2014) A detailed study of the population genetics and relationships of the various groups of Cottus specus in the karst areas.

Day, Starkey and Gerken (2014) Showed that parasitism by Acanthocephala is worse in hypogean populations than in epigean populations in Missouri. Perhaps because of increased cannibalism in the caves.

Day, Gerken and Adams (2014) Population ecology and seasonal demography

Fernholz and Phelps (2016) A study to determine if PIT tags are suitable for use as individual markers in Cottus specus.

Fernholz (2017) A thesis in two chapters. Chapter 1 is effectively the same as Fernholz and Phelps (2016). Chapter 2 is on habitat selectivity and availability and appears not to have been published otherwise.

USFWS (2018) A very detailed account of the conservation measures in place for this species

Chowning (2020) A thesis to determine the best sampling protocols and to investige the life history of Grotto Sculpin.

Conservation Status


Endangered (USFWS 2013)

Endangered (USFWS 2018)


Museum Holdings

All from Burr et al. (2001)

SIUC 19279 (20 specimens, 66–103 mm SL) Cinque Hommes Creek, 1992.

SIUC 18916 (3 specimens) Sculpin Stream, Mystery Cave, 21 April 1991.

SIUC 19904 (3 specimens) Mystery Cave, 7 March 1992.

SIUC 18923 (20 specimens, 52–80 mm SL), Mystery Cave, 1 October 1991.

SIUC 21258 (4 specimens, 57–88 mm SL) Hot Caverns, 4 October 1992.

SIUC 19839 (23 specimens, 51–95 mm SL) Flaming River Cave, 3 July 1992.

SIUC 21260 (8 specimens, 34–56 mm SL) Running Bull Cave, 25 October 1992.

SIUC 20916 (9 specimens, 31–80 mm SL) Tom Moore Cave, 25 October 1992.

Internet Resources

US Fish and Wildlife Service Grotto Sculpin page

Missouri Department of Conservation Grotto Sculpin page

Grotto Sculpin fact sheet

NatureServe conservation account

A brief account

GenBank accession numbers for haplotypes

GR1 KC172892, GR2 KC172893 GR3 GR4

Haplotype MID1 KC172894

Haplotype MID2 KC172895

Haplotype BR1 KC172896

Haplotype BR2 KC172897

Key References

Robins, C.R. Thesis 1954 A taxonomic revision of the Cottus bairdi and Cottus carolinae species group in eastern North American (Pisces, Cottidae)
House, S. Journal Article 1976 Karst and cave distribution in Perry County
Peck, S.B. and Lewis, J.J. Journal Article 1977 Zoogeography and evolution of the subterranean invertebrate faunas of Illinois and southestern Missouri
Williams, J. D. and Howell, W. M. Journal Article 1979 An albino sculpin from a cave in the New River drainage of West Virginia (Pisces: Cottidae)
Vandike, J.E. Journal Article 1985 Movement of shallow groundwater in the Perryville karst area, Southeastern Missouri
Gardner, J.E. Report 1986 Invertebrate fauna from Missouri caves and springs
Walsh, J. Journal Article 1988 Mystery Cave
Walsh, J. Journal Article 1989 Rimstone River Cave
Burr, B.M., Warren, M.L. and Paul, R.J. Journal Article 1992 Cavernicolous sculpins of the Cottus carolinae species group from Mystery Cave, Missouri
Paul, R.J., Burr, B.M. and Warren, M.L. Journal Article 1993 Cavernicolous sculpins of the Cottus carolinae species group from Perry County, Missouri: Cave-life phenomena or speciation ?
Krejca, J. Thesis 1994 Field research to determine the distribution of a cave-adapted Sculpin (Osteichthyes: Cottidae)
Paul, R.J. Thesis 1994 Aspects of cave adaptation in sculpins of the Cottus carolinae species group (Cottidae) in Perry County, Missouri
Krejca, J., Burr, B.M., Warren, M.L. and Paul, R.J. Journal Article 1994 Cavernicolous sculpins of the Cottus carolinae species group (Pisces, Cottidae) from Perry County, Missouri
Krejca, J.K., Burr, B.M., Paul, R.J. and Warren, M.L. Journal Article 1994 Cavernicolous sculpins of the Cottus carolinae species group (Pisces: Cottidae) from Perry County, Missouri
Walsh, J. Journal Article 1995 Exploration of Rimstone River Cave
Coombs, S. Journal Article 1999 Signal detection theory, lateral‐line excitation patterns and prey capture behaviour of mottled sculpin
Coombs, S., Finneran, J.J. and Conley, R.A. Journal Article 2000 Hydrodynamic image formation by the peripheral lateral line system of the Lake Michigan mottled sculpin, Cottus bairdi.
Brison, L.L. Thesis 2001 Experimental analysis of metabolic adaptation of Cottus carolinae in response to photoperiod and food availability
Adams, G. and Burr, B.M Journal Article 2001 Troglomorphic Banded Sculpin (Cottus Carolinae) in Perry County, Missouri: Morphological variation and conservation status
Burr, B.M., Adams, G.L., Krejca, J., Paul, R.J. and Warren, M.L. Journal Article 2001 Troglomorphic sculpins of the Cottus carolinae species group in Perry County, Missouri: Distribution, external morphology and conservation status
Coombs, S., Braun, C.B. and Donovan, B. Journal Article 2001 The orienting response of Lake Michigan mottled sculpin is mediated by canal neuromasts.
Aley, T., Ashley, D.C., Elliott, W.R., McGlimsey, M., Weaver, D. and Beard, J. Book 2002 Conserving Missouri's caves and karst
Kanter, M.J. and Coombs, S. Journal Article 2003 Rheotaxis and prey detection in uniform currents by Lake Michigan mottled sculpin (Cottus bairdi)
Elliott, W.R. Book 2003 A guide to Missouri's cave life
Adams, G. Thesis 2005 Morphology, genetics and physiology of a troglomorphic sculpin, Cottus carolinae
Kinziger, A.P., Wood, R.M. and Neely, D.A. Journal Article 2005 Molecular systematics of the genus Cottus (Scorpaeniformes: Cottidae)
Robins, C.R. Journal Article 2005 Cottus kanawhae, a new cottid fish from the New River System of Virginia and West Virginia
Niemiller, M.L., Glorioso, B.M. and Miller, B.T. Journal Article 2006 An eastern and subterranean maximum size record of the banded sculpin, Cottus carolinae, from Tennessee
Kerfoot, J.R. and Schaefer, J.F. Journal Article 2006 Ecomorphology and habitat utilization of Cottus species
Kinziger, A.P., Goodman, D.H. and Studebaker, R.S. Journal Article 2007 Mitochondrial DNA variation in the Ozark Highland members of the Banded Sculpin Cottus carolinae complex
Elliott, W.R. Journal Article 2007 Zoogeography and biodiversity of Missouri cave and karst
Adams, G., Day, J., Gerken, J.E. and Johnson, C.R. Report 2008 Population ecology of the Grotto Sculpin, Cottus carolinae, in Perry County, Missouri
Aley, T., Aley, C., Moss, P. and Hertzler, T. Journal Article 2008 Hydrogeological characteristics of delineated recharge areas for 40 biologically significant cave and spring systems in Missouri, Arkansas, Oklahoma and Illinois
Johnson, C.R., Day, J.L. and Adams, G. Journal Article 2008 Life history characteristics of Grotto Sculpin (Cottus carolinae) in cave and surface streams of Perry County, Missouri
Gerken, J.E. and Adams, G. Journal Article 2008 Habitat use by Grotto Sculpin (Cottus carolinae), a troglomorphic fish in Perry County, Missouri
Day, J.L., Johnson, C.R., Gerken, J.E. and Adams, G. Journal Article 2008 Population ecology of Grotto Sculpin (Cottus carolinae) in cave and resurgence streams
Fox, J.T., Adams, G.L., Sharum, M.and Steelman, K. Journal Article 2010 Passive sampling of bioavailable organic chemicals in Perry County, Missouri cave streams
Crabill, T., Simmons, B., Marquardt, S. and Salveter, A. Web Page 2013 Recovering aquatic life in Missouri
U.S. Fish and Wildlife Service Report 2013 Endangered and threatened wildlife and plants: Determination of endangered species status for the Grotto Sculpin (Cottus specus) throughout its range
Perry County Community Economic and Environment Committee Report 2013 Protecting our water to protect our community
U.S. Fish and Wildlife Service Web Page 2013 U.S. Fish and Wildlife Service lists the Grotto Sculpin as endangered
Crites, J., and Schubert, H. Report 2013 Perry County karst project: Summary and future management implications for Grotto Sculpin.
Moss, P. Journal Article 2013 Recharge area delineations and hazard and vulnerability mapping in Perry County, Missouri
Industrial Economics Incorporated Report 2013 Economic analysis of critical habitat designation for the Grotto Sculpin
Adams, G., Burr, B.M., Day, J. and Starkey, D.E. Journal Article 2013 Cottus specus, a new troglomophic species of Sculpin (Cottidae) from southeastern Missouri
Day, J., Starkey, D.E. and Gerken, J.E. Journal Article 2014 Prevalence of parasitism in the Grotto Sculpin (Cottus specus), a new species of cave-adapted fish from southeastern Missouri, USA
Day, J., Starkey, D.E., Adams, G., Brummett, S. and Keeney, D. Journal Article 2014 Population genetics of grotto sculpin (Cottus specus), a new cave-adapted fish species
Day, J., Gerken, J.E. and Adams, G. Journal Article 2016 Population ecology and seasonal demography of endangered grotto sculpin (Cottus specus)
Fernholz, J. and Phelps, Q.E. Journal Article 2016 Influence of PIT tags on growth and survival of Banded Sculpin (Cottus carolinae): Implications for endangered Grotto Sculpin (Cottus specus)
Ruppert, J.L.W., James, P.M.A., Taylor, E.B., Rudlofsem, T., Veillard, M., Davis, C.S., Watkinson, D. and Poesch, M.S. Journal Article 2017 Riverscape genetic structure of a threatened and dispersal limited freshwater species, the Rocky Mountain Sculpin (Cottus sp.)
Gebhard, A.E and Perkin, J.S. Journal Article 2017 Assessing riverscape-scale variation in fish life history using banded sculpin (Cottus carolinae)
Fernholz, J. Thesis 2017 Influence of PIT tags on growth and survival of Banded Sculpin (Cottus carolinae): Implications for endangered Grotto Sculpin (Cottus specus)
U.S. Fish and Wildlife Service Report 2018 Endangered and Threatened Wildlife and Plants - Designation of Critical Habitat for the Grotto Sculpin (Cottus Specus)
Fernholz, J. Thesis 2018 Influence of Pit Tags on growth and survival of Banded Sculpin (Cottus carolinae): Implications for endangered Grotto Sculpin (Cottus Specus).
Baek, S.Y., Kang, J.H., Jo, S.H., Jang, J.E., Byeon, S.Y., Wang, J.H., Lee, H.G., Choi, J.K. and Lee, H.J. Journal Article 2018 Contrasting life histories contribute to divergent patterns of genetic diversity and population connectivity in freshwater sculpin fishes
Wells, W.G., Johnson, T.C., Gebhard, A.E., Paine, R.T.R., Hix, L.A., Ferrell, H.N., Engle, A.N. and Perkin, J.S. Journal Article 2018 March of the sculpin: measuring and predicting short‐term movement of banded sculpin Cottus carolinae
Niemiller, M.L., Taylor, S.J., Slay, M.E. and Hobbs, H.H. III Book Section 2019 Biodiversity in the United States and Canada
Chowning, M.E. Thesis 2020 Establishing a sampling protocol and investigating the life history of the federally endangered Grotto Sculpin (Cottus specus) in the karst systems of Perry County, Missouri