Mississippi Green Watersnake

Image of a Mississippi green watersnake
Species of Conservation Concern
Scientific Name
Nerodia cyclopion
Colubridae (nonvenomous snakes) in the order Squamata (lizards and snakes)

A medium-sized, dark-colored, heavy-bodied snake, the Mississippi green watersnake was once somewhat common in southeastern Missouri but is now probably extirpated. The back is greenish brown with numerous small, obscure olive-brown or dark brown markings. The belly is dark gray with numerous yellow half-moon-shaped markings. Although not venomous, watersnakes bite viciously to defend themselves and also secrete a strong-smelling musk from glands at the base of the tail.

Similar species: A number of other watersnakes live in Missouri's Bootheel. They all have some combination of prominent bands on the back, or a plain yellow belly, or a yellow belly strongly marked with black patches. Watersnakes are often confused with the venomous northern cottonmouth (Agkistrodon piscivorus) and needlessly killed. The cottonmouth is more heavy-bodied, with a larger, chunky head; has a facial pit between the nostril and eye on either side of the head; is darker; and has a light line from each eye to the corner of the mouth.

Other Common Names
Mississippi Green Water Snake

Length: 30 to 45 inches.

Where To Find
Mississippi Green Watersnake Distribution Map

Restricted to the southeastern corner of the state; probably extirpated.

Primarily a swamp-dwelling snake. In Missouri, it prefers the cypress swamps and river sloughs of the Mississippi Lowlands.This harmless, semiaquatic snake was once somewhat common in southeastern Missouri but is now quite rare. Due to drastic reductions in native cypress swamps, this species is endangered in Missouri and has not been seen here for many years. It is probably extirpated from our state.

This watersnake feeds mainly on fish, salamanders, frogs, and crayfish.

Endangered and probably extirpated in Missouri. Some individuals were spotted in southern Dunklin County in 1994, and several dead specimens have been collected from roads just across the border in Mississippi County, Arkansas. There is reason to hope that some Mississippi green watersnakes may still be found on the Missouri side of the border, enriching our state with their presence.

Life Cycle

Active between late March and October, usually on warm days, often basking on branches overhanging water. They hunt for food during early evening or at night when the weather is hot. Courtship and mating apparently occur in April or May. Females give birth to live young (not eggs) during August and early September, with the litter containing some 10-20 young.

Often when we think of our interactions with animals, we focus on what they mean to us: Can we eat them, do they harm us, and so on. But with most declining species, the situation is reversed: Our human activities, such as draining swamps, have eliminated most of their ancestral habitat.

As predators, watersnakes control populations of the animals they consume. But snakes are preyed upon themselves. Their defenseless newborns are gobbled by animals ranging from large frogs and fish to other snakes and birds and mammals. Adults are eaten by predatory mammals and birds.

Media Gallery
Similar Species
About Reptiles and Amphibians in Missouri
Missouri’s herptiles comprise 43 amphibians and 75 reptiles. Amphibians, including salamanders, toads, and frogs, are vertebrate animals that spend at least part of their life cycle in water. They usually have moist skin, lack scales or claws, and are ectothermal (cold-blooded), so they do not produce their own body heat the way birds and mammals do. Reptiles, including turtles, lizards, and snakes, are also vertebrates, and most are ectothermal, but unlike amphibians, reptiles have dry skin with scales, the ones with legs have claws, and they do not have to live part of their lives in water.