What venomous snake is also called the water moccasin?

The venomous snake also called the water moccasin is the cottonmouth, Agkistrodon piscivorus.

Cottonmouths are pit vipers native to the southeastern United States. The common name comes from their defensive display: when threatened, they may gape widely and expose the striking white lining of the mouth. “Water moccasin” is another widely used common name for the same species.

The species name piscivorus means “fish-eating,” reflecting part of its diet. Cottonmouths are semiaquatic and may live around swamps, marshes, ponds, streams, and other wetlands, but they also eat frogs, lizards, birds, mammals, and other prey. They are capable swimmers and can occur in both freshwater and coastal habitats.

People often mistake harmless watersnakes for cottonmouths, especially because both may be found near water. The name “water moccasin” can add confusion, so identification should rely on expert guidance rather than appearance alone. Cottonmouths are pit vipers in the family Viperidae, alongside copperheads and rattlesnakes.