Eastern Cottonmouth
Agkistrodon piscivorus piscivorus

*** VENOMOUS ***

Venomous Snake Bite Information || Cottonmouth look-a-likes || Copperhead look-a-likes

Common Name:

Eastern Cottonmouth

Scientific Name:

Agkistrodon piscivorus piscivorus



Agkistrodon is derived from the Greek word ancistron which means "fishhook". This is in reference to recurved fangs.


piscivorus is derived from the Latin words piscis which means "fish" and voro which means "to devour".

Vernacular Names:

Water moccasin, black moccasin, black snake, blunt-tail moccasin, congo, copperhead, cottonmouth water moccasin, cotton-mouthed snake, gapper, highland moccasin, lowland moccasin, mangrove rattler, moccasin, water viper, rusty moccasin, saltwater rattler, stub-tail, stump moccasin, stump-tail viper, swamp lion.

Average Length:

30-48 in. (76-122 cm)

Virginia Record Length:

60.5 in. (153.6 cm)

Record length:

74 in. (188 cm)

PHYSICAL DESCRIPTION: The length of this species is 2.5-4 feet *2077,882*. They may reach 6 feet *2077*. This is a large aquatic snake. It is olive, brown or black above with the belly lighter. The crossbands have dark, more- or-less distinct borders. The centers of the crossbands are often invaded by a lighter ground color. Old adults may be completely dark and unpatterned. The snout is light in color and usually has a vertical dark line on each side of the rostrum. The scales are weakly keeled *882*. Heads are triangular with the dorsum portion being flat; neck is much narrower; males are larger than the females; juveniles have the same patterns as adults but are brighter in color and the crossbands a more prominent; the body color may be more of a pinkish color and they have the sulfur yellow tip of the tail *10760*.

REPRODUCTION: The females are sexually mature in their third year, but prob- ably don't mate until the fourth year thereafter they mate biannually *2077*. There are 1-15 young per litter *2077,1101*. They are born alive from mid- August to mid-September *1101*. After a gestation period of 4-6 months *2077*. The young have a broad dark band through the eye and a yellow tip on the tail *882*. The females tend to aggregate if gravid or attending young. This is probably to guard the young by banding together to exhibit more strength *2077*. The young are 10-13 inches at birth *1014*. They are viviparous, mate mainly in the spring and occassionally in the fall; observations of birth occurred in September; females appear to have a biennal to triennial cycle of litter production *10760*.

BEHAVIOR: They are fond of basking on a rock, log, or stump during the day. They are very pugnacious *2077*. If approached, this species will stand its ground *2077,1013,10760*, or crawl away very slowly *882*. If it stays, it will coil *2077*. It slowly vibrates its tail *2077,882*, and will open its mouth, or gape, to reveal its white mouth *2077,882,1013*. It will strike repeatedly against humans *2077*. When swimming, it carries its head out of the water and appears to be rather bouyant *1013*. Males are known to preform a combat dance; generally not aggressive but do not hesitate to strike if molested; they emit a musk from a gland at the base of the tail and increase the amount given off when captured *10760*.

CONFUSING SPECIES: The northern water snake (Nerodia sipedon) is often mistaken for the cottonmouth, it can be told apart because the crossbands on the anterior of the snake do not widen at the ends; also mistaken for the cottonmouth is the nonvenomous Nerodia taxispilota which has most of its body below the water when in motion and only the head showing when motionless, unlike the cottonmouth that has the entire body on the surface of the water *10760*.

References for Life History

  • 882 - Conant, R., 1958, A field guide to reptiles and amphibians of the United States and Canada east of the 100th Meridian, 366 pgs., Houghton Mifflin Co., Boston, MA
  • 1013 - Jackson, J.J., 1983, Snakes of the Northeastern United States, 111 pgs., Ext. Serv., Univ. of GA, Athens, GA
  • 1014 - Martof, B.S., Palmer, W.M., Bailey, J.R., Harrison, III J.R., 1980, Amphibians and Reptiles of the Carolinas and Virginia, 264 pgs., UNC Press, Chapel Hill, NC
  • 1101 - Mitchell, J. C., 1974, Snakes of Virginia, Virginia Wildl., Vol. 35, Num. 2, pg. 16-19
  • 2077 - Russ, W.P., 1973, The rare and endangered terrestrial vertebrates of Virginia, Ph.D. dissertation, Virginia Polytechnic Institute and State Univ., Blacksburg, 339 pgs.
  • 10760 - Mitchell, J. C., 1994, The Reptiles of Virginia, 352 pgs., Smithsonian Institution Press, Washington, DC


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Verified County/City Occurrence

Chesapeake City
Chesterfield County
Dinwiddie County
Newport News City
Prince George County
Suffolk City
Surry County
Sussex County
Virginia Beach City
York County
Verified in 10 Counties/Cities.


Virginia is home to 28 species of frogs and toads.


We have a large diversity of salamanders consisting of 56 different species and subspecies.


Virginia is home to 9 native lizard species and two introduced species, the Mediterranean Gecko and the Italian Wall Lizard.


The Commonwealth is home to 34 species and subspecies of snake. Only 3 species are venomous.


Virginia has 25 species and subspecies of turtle. Five of these species are sea turtle.