THE CENTER FOR NORTH AMERICAN HERPETOLOGY

Reptilia    Squamata (part-snakes)    Colubridae  

Eastern Indigo Snake
Drymarchon couperi (Holbrook, 1842)
DRY-mar-kon — KOO-per-eye

SSAR 9th Edition Comments:
 Krysko et al. (2016, Zootaxa 4138: 549–569) described a new taxon, D. kolpobasileus, based on morphological differences of the skull and mtDNA sequence data from D. couperi. Guyer et al. (2019, Zootaxa 4695: 168–174) were unable to confirm head-shape differences between D. kolpobasileus and D. couperi, and Folt et al. (2019, PLoS One 14: e0214439) examined lineage structure using nDNA and found it failed to support conclusions from mtDNA alone. Both the Guyer and Folt studies recommend against recognition of D. kolpobasileus. (Boundy, Jeff, Frank T. Burbrink, and Sara Ruane. 2025. Squamata (excluding lizards) – Snakes. Pages 38-54 in Kirsten E. Nicholson (Editor), Scientific and Standard English Names of Amphibians and Reptiles of North America North of Mexico, with Comments Regarding Confidence in Our Understanding, 9th Edition. Society for the Study of Amphibians and Reptiles, Lawrence, Kansas. 87 pp.)

Range maps are based on curated specimens and provided gratis by CNAH.
(Created by Travis W. Taggart; Version: 2023.04.08.20.40.09)
Download GeoJSON polygon range file: - 0.3 MB

Province/State Distribution:
United States: Alabama Florida Georgia Mississippi

Taxonomic Etymology:
Named in honor of a pioneering American herpetologist.
Drymarchon — From Greek drymarchos (δρυμάρχων), “lord of the forest,” from drymos (δρυμός), “wood” or “forest,” and archon (ἄρχων), “ruler.” The name means “ruler of the forest,” referencing the snake’s large size and terrestrial habits.
couperi — A patronym honoring James H. Couper (1794-1866), a plantation naturalist with interests extending beyond agriculture—collecting live specimens of reptiles, mollusks, and plants. In 1842, supplied John Edwards Holbrook with the type specimen of the Eastern Indigo Snake (Drymarchon couperi) from south of the Altamaha River

First instance(s) of published English names:
Couper's Snake (Spilotes couperi: Yarrow, Henry C. 1882. Check list of North American Reptilia and Batrachia with catalogue of specimens in U. S. National Museum. Bulletin of the United States National Museum (24):1-249); Georgia Snake (Spilotes erebennus: Yarrow, Henry C. 1882. Check list of North American Reptilia and Batrachia with catalogue of specimens in U. S. National Museum. Bulletin of the United States National Museum (24):1-249); Indido Snake (Spilotes corais couperii: Beyer, George. 1900. Louisana herpetology. Proceedings of the Louisiana Society of Naturalists 1897-1899():24-46); Indigo Snake (Spilotes corais couperi: Brown, Arthur, E. 1902. Report of the Board of Directors. Pages 5-22 in Thirtieth Annual Report of the Board of Directors of the Zoological Society of Philadelphia. Allen, Lane, and Scott, Philadelphia, Pennsylvania. pp.); Gopher-snake (Drymarchon corais couperi: Stejneger, Leonhard H. and Thomas Barbour. 1917. A Checklist of North American Amphibians and Reptiles. Harvard University Press, Cambridge, Massachusetts. pp.); Indigo-snake (Drymarchon corais couperi: Stejneger, Leonhard H. and Thomas Barbour. 1917. A Checklist of North American Amphibians and Reptiles. Harvard University Press, Cambridge, Massachusetts. pp.); Indigo Snake (Drymarchon corais couper: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Indigo Snake (Drymarchon corais couperi: Schmidt, Karl Peterson and D. D. Davis. 1941. Field Book of Snakes of the United States and Canada. C.P. Putnam and Sons, New York. 365pp.); Indigo Snake (Drymarchon corais: Schmidt, Karl P. 1953. A Check List of North American Amphibians and Reptiles. 6th Edition. University of Chicago Press, Chicago, Illinois. 280pp.);

Taxon Links:

  
Catalog of American Amphibians and Reptiles
  
The Reptile Database
  
NatureServe
  
iNaturalist
  
GenBank
  
USGS - Nonindigenous Aquatic Species Database

Selected References:
1842 Holbrook, John E. North American Herpetology; or Description of the Reptiles Inhabiting the United States. Second Edition. Volume 3. J. Dobson, Philadelphia, Pennsylvania. 128pp.
1981 McCranie, James R. Drymarchon, D. corais. Catalogue of American Amphibians and Reptiles (267):1-4
1991 Collins, Joseph T. Viewpoint: A new taxonomic arrangement for some North American amphibins and reptiles Herpetological Review 22(2):42-43
2001 Wüster, Wolfgang, José Luís Yrausquin, and Abraham Mijares. A new species of indigo snake from north-western Venezuela (Serpentes: Colubridae: Drymarchon). Herpetological Journal 11(4):157-165
2014 Crother, Brian I. The bold taxonomic hypotheses of Collins (1991): 23 years later. Herpetological Review 45(2):268-272
2016 Krysko, Kenneth L., Michael C. Granatosky, Leroy P. Nunez, and Daniel J. Smith. A cryptic new species of Indigo Snake (genus Drymarchon) from the Florida Platform of the United States. Zootaxa 4138(3):549-569
2019 Folt, Brian, Javan Bauder, Stephen Spear, Dirk Stevenson, Michelle Hoffman, Jamie R. Oaks, Perry L. Wood, Jr., Christopher Jenkins, David A. Steen, and Craig Guyer. Taxonomic and conservation implications of population genetic admixture, mito-nuclear discordance, and male-biased dispersal of a large endangered snake, Drymarchon couperi. PLoS One 14(3):e0214439
2019 Guyer, Craig, Brian Folt, Brian Folt, Michelle Hoffman, Dirk Stevenson, Scott M. Goetz, Melissa A. Miller, and James C. Godwin. Patterns of head shape and scutellation in Drymarchon couperi (Squamata: Colubridae) reveal a single species. Zootaxa 4695(2):168–174

THE CENTER FOR NORTH AMERICAN HERPETOLOGY — Accessed: Friday 05 December 2025 16:59 CT