Max Nickerson photo.

Scientific name: Agkistrodon piscivorus piscivorus.

Description: Average adult size is 20-48 inches (51-121 cm), record is 74.5 inches (189 cm). A dark-colored, heavy-bodied snake. Juveniles are brightly colored with reddish-brown crossbands on a brown groundcolor. The dark crossbands contain many dark spots and speckles. The pattern darkens with age so adults retain only a hint of the former banding or are a uniform black. The scales are keeled. The broad, dark, facial stripe is not well-defined in large adults. The snout tip lacks vertical dark markings. The head is thick and distinctly broader than the neck, and when viewed from above, the eyes cannot be seen. The top of head in front of the eyes is covered with large plate-like scales. The pupil is vertical (catlike). There is a deep facial pit between the nostril and the eye.

Young juvenile cottonmouths have a sulfur-colored tail.

Cottonmouth: Left to right: Top of the head (notice the large plate-like scales on the top of the head, and that the eyes cannot be seen from the top); underside of the head (chin and throat).

Cottonmouth: Left to right: Side of the head (notice the facial pit between the eye and the nostril); front (face view) of the head.

Range: Found the extreme western panhandle of Florida. Outside of Florida it is found to the north and east through Alabama to central Georgia and Virginia.

Habitat: Cottonmouths can be found along streams, springs, rivers, lakes, ponds, marshes, swamps, sloughs, reservoirs, retention pools, canals, and roadside ditches. It occasionally is found far from water.

Comments: . Cottonmouth bites can be quite dangerous. The victim should seek immediate medical care from a physician or hospital experienced in treating snakebite.

When threatened, the cottonmouth may respond by coiling its body and opening its mouth as though ready to bite — see photograph in Florida cottonmouth, Agkistrodon piscivorus conanti. The exposed white interior of the mouth is what gave rise to the common name, ‘cottonmouth.’ Given the chance, the cottonmouth usually will retreat. This open mouth threat display has led to the widespread belief that cottonmouths are aggressive snakes.

Some people believe cottonmouths lie in wait on tree limbs overhanging water so they can drop into boats. These are usually cases of mistaken identity. The harmless brown watersnake often basks on tree limbs over the water, and when frightened by a rapidly approaching boat, they will escape by throwing themselves off the limb and into the water. Occasionally the watersnake's attempt to flee comes too late and it falls not into the water, but into the boat.

Cottonmouths feed on fish, frogs, mice, rats, and other small mammals.

Juvenile cottonmouths have a bright, sulfur-colored tail which they hold erect and wiggle like a caterpillar to attract prey within striking range.

Comparison with other species: Because they both occur around bodies of water, cottonmouths are often confused with harmless watersnakes. Though the cottonmouth occurs throughout Florida, it is not as abundant as the many species of harmless watersnakes that occur in the same habitats. Many Florida residents do not even realize that watersnakes exist. As a consequence, every large dark-colored snake found near water is counted, and usually killed, as a ‘cottonmouth.’ There is little justification for this error for cottonmouths can easily be distinguished from watersnakes. If the head is viewed from above, the eyes of cottonmouths cannot be seen while the eyes of watersnakes are visible; cottonmouths have elliptical pupils and watersnakes have round pupils; cottonmouths have a facial pit between the nostril and the eye, and watersnakes have none. Brightly-colored baby cottonmouths sometimes are mistaken for copperheads, which occur in Florida only in the panhandle. The two species are easy to distinguish because the dark bars on juvenile cottonmouths have numerous dark spots and speckles in them, while the dark bars on the copperhead have no dark spots or at most only one. In additioin, the eye of the copperhead is not obscured by the dark facial band typical of the cottonmouth.

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