Squamata suborder Serpentes
Agkistrodon piscivorus -- Cottonmouth
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Purple shade indicates vouchered specimens. Light blue (cyan)
shade indicates photographic records. Yellow shade indicates verified
sighting. Slanted hatch indicates pre-1980 records only
NOTE: Not all specimens upon which these maps are based have been verified.
Key Characters: Nine large symmetrical plates on top of head; elliptical pupil; pit between eye and nostril; back uniformly black or with ragged dark crossbands; back scales strongly keeled; anal plate not divided.
Similar Species: Copperhead, northern water snake, Mississippi green water snake.
Subspecies: Western cottonmouth, A. p. leucostoma.
Description: Large (up to 159 cm TL), stout-bodied venomous snake. Juveniles and young adults have 12-18 dark crossbands on an olive or dark brown back and a dark stripe from snout through eye and upper lip. With age, adults become uniformly dark olive or black. Belly tan to gray and heavily marked with black. The sulfur yellow tail tip of newborn darkens with maturity.
Habitat: Cypress-tupelo swamps, sloughs, and oxbow lakes of extreme southern counties.
Natural History: Active April through October, often sunning on logs extending into water. When threatened, the mouth is opened in an exaggerated manner to expose the starkly contrasting white mouth lining. Opportunistic predators of fish, amphibians, other reptiles, and small mammals. Three to eight young born in late August or early September. Newborn 20-30 cm TL. Adults have few enemies other than human beings, but young are eaten by large fish, snapping turtles, other snakes, wading birds, and mammals.
Status: Has declined with draining and clearing of bottomland swamps and sloughs, but remains abundant in relatively undisturbed habitats (see distribution map, above).