Many people wonder if “cottonmouths” and “water moccasins” are distinct snake species. This common confusion highlights the need to understand their correct terminology and characteristics.
Clarifying the Names: One Snake, Many Monikers
“Cottonmouth” and “water moccasin” are common names for the same venomous snake species, Agkistrodon piscivorus. Regional variations and common usage led to these different names, with “cottonmouth” often preferred by herpetologists. The scientific name, Agkistrodon piscivorus, means “fish eater,” reflecting its diet.
Key Identification Marks
Cottonmouths are heavy-bodied snakes, typically 2 to 4 feet long, though some reach 6 feet. They have a distinctly triangular head, broader than their neck due to venom glands. As pit vipers, they possess heat-sensing pits between their eyes and nostrils, aiding prey detection. Their pupils are elliptical, or cat-like, unlike many non-venomous water snakes with round pupils. Coloration varies, from dark brown, black, or olive, often with broad, dark crossbands that may fade in older individuals; their characteristic white mouth interior, displayed when threatened, gives them their common name.
Where They Reside
Cottonmouths are semi-aquatic snakes, found in or near water throughout the southeastern United States. Their habitat includes swamps, marshes, ponds, lakes, ditches, and slow-moving streams. Their geographical range extends from southeastern Virginia to Florida and west to central Texas, even reaching southern Illinois and Indiana. These snakes often bask on logs, rocks, or branches at the water’s edge.
Understanding Their Behavior
Cottonmouths are not aggressive; their actions are defensive responses to perceived threats. When threatened, they exhibit a defensive display by coiling their body, vibrating their tail, and opening their mouth wide to reveal the white interior. This “cottonmouth” display serves as a clear warning. They are opportunistic predators, primarily eating fish, amphibians, small mammals, and occasionally birds or other snakes. Cottonmouths often hunt near water, employing ambush tactics, and are particularly active at night.
Venom and Encounter Safety
Cottonmouths are venomous snakes, delivering hemotoxic venom that affects blood and tissue. While rarely fatal, bites cause significant pain, swelling, and tissue damage, sometimes requiring antivenom. Symptoms include localized pain and swelling; some bites may be “dry” with minimal venom injected. Systemic symptoms like nausea or abnormal blood clotting are less common.
If an encounter occurs, observe the snake from a distance and avoid handling or killing it. In case of a bite, immediate medical attention is necessary. Remain calm, keep the bitten limb immobilized and below heart level, and remove any constrictive clothing or jewelry. Do not apply a tourniquet, cut the wound, suck out venom, or apply ice, as these actions can worsen the situation.