Northern Cottonmouth
Agkistrodon piscivorus • Order: Squamata; Suborder: Serpentes; Family: Viperidae; Subfamily: Crotalinae; Genus: Agkistrodon; Species: piscivorus
Venomous Status
Venomous (Solenoglyphous fangs)
Danger Level
Extremely Dangerous; a bite is a medical emergency that can lead to permanent tissue damage or death if untreated.
Geographic Range
Southeastern United States, ranging from southeastern Virginia south to Florida and west to eastern Texas and Oklahoma.
Conservation Status
Least Concern (IUCN); however, they face threats from habitat loss and persecution by humans.
Physical Description
Heavy-bodied pit viper. Features dark crossbands on a dull brown or olive background. The pattern often fades to nearly black in older adults. Note the vertical pupils, heat-sensing pits between the eye and nostril, and a distinct dark stripe through the eye.
Size & Dimensions
Typically 30–48 inches (76–122 cm). Rare specimens can exceed 70 inches. The specimen in the image appears to be an adult.
Habitat
Semiaquatic; found in swamps, marshes, sluggish streams, lakes, and drainage ditches. Often found basking on logs or rocks near the water's edge.
Behavior & Temperament
Known for a defensive display where it opens its mouth wide to reveal a white 'cotton' lining. Semi-aquatic, active both day and night depending on temperature, and generally stands its ground rather than fleeing.
Diet & Feeding
Generalist carnivore; feeds on fish, frogs, turtles, small mammals, birds, and other snakes. Uses a combination of ambush and active foraging.
Reproduction
Ovoviviparous (gives birth to live young); typical litter size is 6–10 young, born in late summer or early fall.
Venom & Safety
Venom Type
Primarily hemotoxic and cytotoxic; causes tissue destruction, swelling, and severe pain.
First Aid Advice
Seek immediate medical attention at a hospital. Keep the bitten limb immobile and at or slightly below heart level. Do not use ice, tourniquets, or attempt to suck out the venom. CroFab antivenom is the standard treatment.
Look-alikes
Commonly confused with non-venomous Nerodia species (Water Snakes). Distinguishable by the Cottonmouth's vertical pupils, heat pits, and the way it swims with its entire body buoyant on the water surface.
Conservation Status
Least Concern (IUCN); however, they face threats from habitat loss and persecution by humans.
Cultural Significance
Often unfairly maligned as aggressive; plays a vital role in controlling prey populations in wetland ecosystems.
Notable Features
The white interior of the mouth used for intimidation and the ability to bite underwater are unique characteristics among North American vipers.