Other common names
Mississippi Green Water Snake
Most adult Mississippi Green Watersnakes are about 30-55 inches (76-140 cm) in total length. Adults are stout-bodied snakes with a dark greenish background color and several narrow darker markings alternating down the back and sides. These markings typically fade as the animal ages and may disappear completely. The head is large, with small scales between the eye and the upper lip scales. Juvenile coloration is similar to that described for adults, but the dark markings on the back and sides are much more vivid.
The presence of Mississippi Green Watersnakes in the state is represented by only a few records from coastal Escambia County in the far western Panhandle. These snakes have not been recorded from anywhere else in Florida.
Assessment of risk to people and pets
Non-venomous. Mississippi Green Watersnakes are not dangerous to people or pets, but they will readily bite to defend themselves. These snakes are not aggressive and avoid direct contact with people and pets. Virtually all bites occur when the snakes are intentionally molested.
Comparison with other species
Florida Cottonmouth (Agkistrodon conanti) Venomous If the head is viewed from above, the eyes of cottonmouths cannot be seen while the eyes of watersnakes are visible. Cottonmouths have vertically elliptical (cat-like) pupils, whereas watersnakes have round pupils. Cottonmouths have a facial pit between the nostril and the eye, whereas watersnakes do not.
Southern Watersnake (Nerodia fasciata) Non-venomous Southern Watersnakes have broad black, brown, or red crossbands (often bordered with black) down the back and a dark stripe that extends from the eye to the angle of the jaw.
Florida Green Watersnake (Nerodia floridana) Non-venomous Florida Green Watersnakes are dark green with small dark speckling and have small scales between the eye and the scales on the upper lip. They are only found east of Okaloosa County in the Panhandle.
Brown Watersnake (Nerodia taxispilota) Non-venomous Brown Watersnakes have squarish dorsal blotches along the entire body.
Most adult Mississippi Green Watersnakes are about 30-45 inches (76-114 cm) in total length, with a record length of 51 inches (129.5 cm). Adults are stout-bodied with a dark greenish background color and several narrow darker markings that alternate down the back and along the sides. These markings typically fade as the animal ages and may disappear completely in older individuals. The belly is patterned with light half-moons on a darker green, gray, or black background. The head is large, with 1-3 small scales between the eye and the upper lip scales. The pupil is round. The scales on the body are strongly keeled (each scale has a prominent raised ridge), and there are 27-29 dorsal scale rows at midbody. Juvenile coloration is similar to that described for adults, but the dark markings on the back and sides are much more distinct.
Mississippi Green Watersnakes typically inhabit the calm slow-moving waters of cypress swamps, sloughs, streams, lakes, ponds, inundated woodlands, and other similar areas.
When approached, Mississippi Green Watersnakes will typically flee for shelter or into the water. However, if they are cornered, both juveniles and adults will strike at the attacker. If grabbed or pinned, they will typically bite and release a foul-smelling musk from a pair of glands in the base of the tail. Nonetheless, these snakes are not aggressive, and striking is only used in defense as a last resort.
Mississippi Green Watersnakes feed primarily on amphibians and freshwater fishes. These snakes are not constrictors and overpower their prey by simply grabbing it in their jaws and quickly swallowing it alive.
Females typically give live birth to 9-34 young between July and August.
Although active mainly at night, Mississippi Green Watersnakes may be found during the day basking on banks or on mats of vegetation in the water.
Female Mississippi Green Watersnakes grow much larger than males.
Unfortunately, many watersnakes are killed every year by Florida residents who mistake them for cottonmouths. Although cottonmouths occur throughout Florida, they are not nearly as abundant as the eight species of harmless watersnakes (species in the genus Nerodia) that occur in many of the same habitats. If you see a snake in or near the water, most likely it is a harmless watersnake, and it is best for everyone involved to simply leave it alone.
Coastal Escambia County
If you have a new or interesting observation for this species, please email the herpetology staff at the Florida Museum.
Ernst, C.H. and E.M. Ernst. 2003. Snakes of the United States and Canada. Smithsonian Institution Press, Washington, DC. 668 pp.
Gibbons, J.W. and M.E. Dorcas. 2004. North American Watersnakes: A Natural History. University of Oklahoma Press, Norman, Oklahoma. 438 pp.
Krysko, K.L., K.M. Enge, and P.E. Moler. 2019. Amphibians and Reptiles of Florida. University of Florida Press, Gainesville, Florida. 706 pp.
Powell, R., R. Conant, and J.T. Collins. 2016. Peterson Field Guide to Reptiles and Amphibians of Eastern and Central North America. Fourth edition. Houghton Mifflin Harcourt Publishing Company, Boston and New York. xiv + 494 pp.
Share your observations
You can help scientists better understand the biology and distribution of this species by sharing your observations. Send photos or videos of interesting observations, along with associated information, by emailing the herpetology staff at the Florida Museum for documentation in the Museum’s Herpetology Master Database. You can also post your observations on iNaturalist.
Additional helpful information
Do you have snakes around your house? Learn how to safely co-exist with snakes.
Still have questions about snakes or identifications? Feel free to email the herpetology staff at the Florida Museum with your questions or feedback on this profile.