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Here are the 7 Water Snakes Found in Louisiana

With its low-lying topography, humid subtropical climate, and extensive range of coastal marshlands and swamps, Louisiana offers the perfect environment for heat-loving water snakes. Central Louisiana, the Florida parishes, and the greater New Orleans area are especially favorable to snakes seeking plenty of water sources, an abundance of food, and long, hot summers.

Over 40 different species of snakes thrive throughout the state of Louisiana. This article will focus on the true water snakes classified under Genus Nerodia.

Photo collage water snakes in Louisiana

7 Water Snakes in Louisiana

The 7 true water snakes found in Louisiana are the Gulf Salt Marsh snake, Mississippi Green Water snake, Plain-bellied Water Snake, Southern Water Snake, Diamond-backed Water Snake, Brown Water Snake, and the Midland Water Snake.

1. Gulf Salt Marsh Snake

Gulf salt marsh snake
Gulf salt marsh snake | image by Glenn Bartolotti via Wikimedia Commons | CC BY-SA 4.0

Scientific name: Nerodia clarkii

Found in Louisiana coastal parishes only, the Gulf Salt Marsh snake is 15 to 30 inches long when mature and identifiable by three black or dark brown stripes extending along its light brown or pale gray body. The Gulf Salt Marsh snake is nonvenomous, feeding mostly on small crabs and fish living in the brackish marshes and the northern area of Lake Pontchartrain.

They catch prey by hiding in marsh grass and ambushing fish that swim by them. Although sightings of Gulf Salt Marsh snakes are rare, they are not considered at risk of being endangered.

2. Mississippi Green Water Snake

Mississippi Green Water Snake
Mississippi Green Water Snake | Greg Schechter | Flickr | CC BY 2.0

Scientific name: Nerodia cyclopion

Commonly seen in the southern part of Louisiana and the Mississippi/Ouachita River valleys, the Mississippi Green Water snake reaches an adult length of 29 to 41 inches and is nonvenomous. These water snakes prefer marshes and cypress lakes containing an abundant array of aquatic vegetation in which to hide and prey on fish and small reptiles.

Mostly brown on top with a greenish or yellowish brown underbelly, this water snake is active throughout the day, stopping to sun itself occasionally on large logs or rocks and hunting for food at night.

3. Plain-bellied Water Snake

Plain-bellied water snake
Plain-bellied water snake | image by Northeast Coastal & Barrier Network via Flickr | CC-SA 2.0

Scientific name: Nerodia erythrogaster

A large, broad-bodied snake found in all southeastern states, including Florida, eastern North Carolina, and Texas, the plain-bellied water snake can be black, gray, brown, or greenish-gray in color. Its unmarked yellow or red belly differentiates the plain-bellied water snake from other water snakes.

Adults may reach nearly four feet in length. Look for these snakes around natural wetlands, ponds, lakes, and other permanent water sources. When threatened by humans or predators, plain-bellied water snakes will bite and release a foul smell from glands located below their heads. In contrast to other water snakes, the plain-bellied snake won’t hesitate to escape via terrestrial means instead of remaining in the water.

4. Southern Water Snake

Southern Water Snake
Southern Water Snake | NC Wetlands

Scientific name: Nerodia fasciate

The Southern water snake roams in all regions of Louisiana but prefers brackish swamps over other water sources. Typically reaching about 34 inches in length, the nonvenomous Southern water snake is often mistaken for venomous copperheads or cottonmouths because of their bright orange and red colors.

However, markings and colorings vary widely among Southern water snakes, so not all of these snakes look like a copperhead or cottonmouth. Like other Nerodia snakes, the Southern water snake relies on a vomeronasal organ to detect prey by “smelling” protein molecules indicative of animal flesh.

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5. Diamond-backed Water Snake

Diamondback Water Snake
Diamondback Water Snake | k.draper | Flickr | CC BY-ND 2.0

Scientific name: Nerodia rhombifer

The nonvenomous Diamond-backed Water Snake lives mostly along the Mississippi River valley but can also be found in many central U.S. states, including Louisiana, Texas, Missouri, Iowa, and Indiana. Its dark green or dark brown body features a black pattern of lines extending over the back that create diamond shapes.

The belly of the diamond-backed water snake is tan or yellow with several splotches of black appearing randomly from neck to tail. When hunting for fish, this species of snake will wrap its body around a low-hanging branch over the water and periodically dip its head into the water. Although the diamond-backed snake’s bite is not poisonous, it is extremely painful because of its razor-sharp teeth.

6. Brown Water Snake

Brown water snake on log
Brown water snake on log | image by Kelly Verdeck via Flickr | CC BY-ND 2.0

Scientific name: Nerodia taxispilota

Endemic to Louisiana, Mississippi, and other southeastern states, the brown water snake is a large, nonvenomous snake with an unusually narrow neck compared to the size of its head. Brown water snakes are easy to identify because of the brown or black square-shaped mottling running down their backs and yellow bellies spotted with brown or black markings.

Brown water snakes prefer streams and swamps, where they are frequently mistaken for the venomous water moccasin. Both snake species can grow up to three feet long and have thick, intimidating bodies.

7. Midland Water Snake

Midland water snake
Midland water snake | image by Peter Paplanus via Flickr | CC BY 2.0

Scientific name: Nerodia sipedon pleuralis

Midland water snake is a nonvenomous subspecies of Nerodia sipedon, the northern water snake. The range of Midland water snakes encompasses most of the southern and central U.S., including southeastern Mississippi and Louisiana, northwestern Georgia, and southeastern Oklahoma. Light brown or beige-colored with dark red crossbands close to the neck, adult Midland water snakes consume mostly fish, while juveniles eat salamanders, frogs, and small fish.