12 Types of Water Snakes Found in Louisiana! (ID Guide)
“What kinds of water snakes can you find in Louisiana?“
Is it just me, or do you also find water snakes fascinating? There’s something about the way they move across the water that is incredibly interesting. Whenever I am near a pond, marsh, or other body of water, I make sure to look for any water snakes moving about.
Today, you are going to learn about 12 water snakes that live in Louisiana.
The species below are considered either aquatic or semi-aquatic, which means that it’s very likely that you will see them actively swimming or extremely close to water, such as sunning themselves on a bank.
#1. Midland Water Snake
- Nerodia sipedon pleuralis
Identifying Characteristics:
- Adults range from 24 to 50 inches in length.
- Typically light gray in color, but some individuals are reddish.
- Near the head, they have dark crossbands. As you move down the snake, the crossbands are replaced by dark squarish blotches.
This water snake is only found in southeast Louisiana!
Midland Water Snakes prefer slow-moving or standing water such as ponds, lakes, vernal pools, marshes, and slow-moving rivers and streams. They’re most often seen basking on rocks or logs in or near the water.
Common Water Snake Range Map (Midland Water Snakes are subspecies!)
Credit: Virginia Herpetological Society
When disturbed, Midland Water Snakes flee into the water to escape. However, if grabbed or captured, they’re quick to defend themselves. They will release a foul-smelling musk from glands near the base of their tale, flatten their body, and strike the attacker.
While non-venomous, they can deliver a painful bite!
Their saliva contains a mild anticoagulant that can cause bites to bleed, making the injury appear worse. These important defense mechanisms help water snakes survive predators such as raccoons, snapping turtles, foxes, opossums, other snakes, and birds of prey.
Midland Water Snake populations are considered to be stable in Louisiana. However, like many other water snakes, this species faces habitat loss and degradation. Unfortunately, they are also commonly killed by people out of fear.
#2. Plain-bellied Watersnake
- Nerodia erythrogaster
Identifying Characteristics:
- Adults have a thick body and range from 24 to 40 inches in length.
- Solid coloration of gray, brown, olive, or black.
- As the name suggests, they have a plain unmarked underside varying from red to yellow.
- Also called Redbelly, Yellowbelly, Copperbelly, or Blotched Watersnake.
The Plain-bellied Watersnake can be found near various water sources, including rivers, floodplains, lakes, ponds, and wetlands. This species spends an unusual amount of time on land compared with other water snakes found in Louisiana. Especially during hot, humid weather, they can be found in woodlands quite far from a water source.
Plain-bellied Watersnake Range Map
Credit: Virginia Herpetological Society
They feed on BOTH aquatic and terrestrial prey, including crayfish, fish, salamanders, frogs, and other amphibians. Another unusual feature of this species is that they will sit and wait to ambush their prey, especially on land. Almost all other water snakes actively hunt and chase their victims!
The females give birth in August or September to live young. Litters average 18 young, but one of 55 has been reported! These unique water snakes can also produce offspring via parthenogenesis, a form of asexual reproduction in which an embryo develops without fertilization by sperm.

If captured, they release a foul-smelling musk and are not afraid to bite! Plain-bellied Watersnakes are eaten by largemouth bass, egrets, hawks, and sometimes other larger snakes.
#3. Northern Cottonmouth
- Agkistrodon piscivorus
Identifying Characteristics:
- Adults range from 26 to 35 inches in length. Females are typically smaller than males.
- Most individuals are dark gray to black with a broad head, heat-sensing pits between the eyes and nostrils, elliptical pupils, and a blunt snout.
- Some individuals have a brown, gray, tan, or blackish coloration.
- Also commonly called Water Moccasins, Black Moccasins, or Gapers.
Cottonmouths are the ONLY venomous water snake in Louisiana.
Be on the lookout for these water snakes near swamps, marshes, ponds, and slow-moving streams and rivers, as well as flooded fields and drainage ditches. But they aren’t limited to just aquatic habitats. Cottonmouths can also be found in palmetto thickets, pine forests, dune areas, and prairies.
Northern Cottonmouth Range Map
Credit: Virginia Herpetological Society
Since Northern Cottonmouths are typically near water, the bulk of their diet is made up of fish and frogs. But they are opportunistic and will also eat small mammals, birds, turtles, small alligators, and other snakes.
These water snakes have several defensive tactics to warn potential threats to stay away! They often vibrate their tail in the leaf litter, pull their heads up and back, and then open their mouth to hiss and expose a white interior. This particular display is what earned them the name “cottonmouth.“
Since they are venomous, please use extra caution if you come across an unknown water snake. Quite a few species look similar, especially if you just get a glance as one moves across the water.

Luckily, receiving a bite from a Northern Cottonmouth is rare. But when it does happen, it is very serious as their venom destroys tissue. It is rare to die from their bite, but it does cause swelling and bruising and can leave scars.
#4. Gulf Saltmarsh Watersnake
- Nerodia clarkii clarkii
Identifying Characteristics
- Adults range in length from 15 to 36 inches.
- They typically have four longitudinal stripes down the body, including two lighter stripes and two darker stripes.
- Subspecies of the Saltmarsh Watersnake.
You can find these water snakes in Louisiana in coastal salt marshes, brackish estuaries, and tidal mudflats. As their name suggests, they aren’t typically found near freshwater. To hydrate, they usually rely on their prey for their water intake. However, they may also get freshwater from puddles when available.
Saltmarsh Watersnake Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
Salt Marsh Snakes primarily feed on small fish, shrimp, crabs, and other aquatic invertebrates. They are opportunistic and often hunt creatures that are trapped in small puddles created by the outgoing tide. The best time to see one is at night, which is when they are primarily active to avoid predators such as egrets and herons. During the day, you could look for them in dense vegetation.
The Salt Marsh Snake can live up to 20 years and are non-venomous, very secretive, and non-aggressive. Virtually all bites have occurred when people were intentionally harassing the snake.
These docile water snakes are declining and at high risk in parts of their range. Habitat degradation with the development of coastal salt marshes has played a significant role in their decline. Unfortunately, they are also often killed because people confuse them with the venomous cottonmouth.
#5. Mississippi Green Watersnake
- Nerodia cyclopion
Identifying Characteristics:
- Adults have a thick body and range from 30 to 55 inches in length.
- Coloration is dark-green, olive, or brown with a yellowish belly.
- Some individuals have narrow, dark markings alternating down the back and sides.
- Also called Green Watersnake.
The Mississippi Green Watersnake is found in Louisiana in or near calm, slow-moving bodies of water. Habitats include cypress swamps, sloughs, streams, lakes, ponds, and flooded woodlands. Look for them on branches above the water, where they’re often spotted basking in the sun.
Mississippi Green Watersnake Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
These water snakes are primarily nocturnal, and they spend their nights hunting along the banks or shore. They feed on fish, crayfish, frogs, and other freshwater amphibians. They overpower their prey by grabbing it in their jaws and quickly swallowing it alive.
If disturbed, Mississippi Green Watersnakes will typically attempt to flee by entering the water. Though they’re non-venomous, they’re quick to defend themselves. If you capture or grab one, you can expect them to deliver a few quick, repeated bites. Your hands may also get covered in a foul-smelling musk from a pair of glands near the base of the tail.
#6. Broad-banded Watersnake
- Nerodia fasciata confluens
Identifying Characteristics:
- Adults range from 24 to 48 inches in length.
- They are typically black with yellowish, irregular-shaped crossbands.
- Subspecies of the Southern Watersnake.
The Broad-banded Watersnake is found in Louisiana near almost any fresh water source within their range. Look for them everywhere, including lakes, ponds, rivers, marshes, swamps, wetlands, and streams. They’re often spotted on branches overhanging the water, sunning themselves.
Southern Watersnake Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
These water snakes are primarily nocturnal and spend much of their time hunting along the shoreline for frogs and small fish. Like other water snakes, they quickly grab their prey and swallow it alive.
Broad-banded Watersnakes are docile and non-venomous. But if they are captured or grabbed, they will flatten their heads, release a foul-smelling musk from glands near the tip of their tail, and may bite. Unfortunately, they are sometimes killed because they are mistaken for the venomous cottonmouth.
#7. Diamond-backed Watersnake
- Nerodia rhombifer
Identifying Characteristics:
- Adults range from 30 to 48 inches in length.
- Coloration is brown, dark brown, yellowish, or olive green. Look for a dark chain-like pattern down the back.
- Thick body with a yellow belly that has dark half-moons.
The Diamond-backed Watersnake can be found in Louisiana in a variety of freshwater habitats. They generally prefer slow-moving bodies of water with overhanging vegetation such as ponds and swamps and slow rivers and streams.
These water snakes are common in their range and can be spotted on overhanging branches looking for prey, which mainly include frogs and fish. Once they grab their target, they haul it to shore and wait for it to die before consuming it. This behavior is unique as most other water snakes consume their prey alive.
Diamond-backed Watersnake Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
When disturbed, Diamond-backed Watersnakes will quickly flee into the water and dive below the surface to swim away. If captured, they will bite and release a foul-smelling musk from glands near the base of their tail.
They are relatively common and aren’t considered a threatened species. Unfortunately, they are sometimes killed out of ignorance. People often mistake them for venomous cottonmouths and rattlesnakes.
#8. Graham’s Crayfish Snake
- Regina grahamii
Identifying Characteristics:
- Adults range from 18 to 28 inches in length.
- Coloration is a dull brown, yellowish-brown, or gray.
- Look for yellowish-tan stripes down the sides and sometimes a faint tan stripe down the middle of the back.
This water snake is rather reclusive and hard to find in Louisiana.
Look for Graham’s Crayfish Snakes in slow-moving bodies of water such as ponds, prairie streams, marshes, and roadside ditches. They prefer areas with abundant vegetation, rocks, logs, and other debris along the water’s edge, which allows them to hide from predators. Like other water snakes, they can commonly be seen basking on branches overhanging the water.
Graham’s Crayfish Snake Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
As the name suggests, Graham’s Crayfish Snakes primarily feed on crayfish. They hunt exclusively for individuals that recently molted and temporarily have soft bodies. However, they’ll also prey on fish and amphibians, including tadpoles and frogs.

Like many other water snakes, this species is often mistaken for cottonmouths and killed, even though they are MUCH smaller.
#9. Glossy Swampsnake
- Liodytes rigida
Identifying Characteristics:
- Adults range from 14 to 24 inches in length.
- Coloration is a glossy brownish to olive with yellow lip scales. There are sometimes two dark or black stripes running down the back.
- The underside is yellow with two rows of black half-moons or dots.
Glossy Swampsnakes inhabit and rarely leave slow-moving waterways such as cypress swamps, roadside ditches, ponds, lakes, marshes, streams, and rivers. These water snakes are quite secretive and often hide under logs and debris near the water or inside crayfish burrows. Your best chance to see one might be on roadways during or after a heavy rain.
Glossy Swampsnake Range Map
Credit: U.S. Geological Survey, Department of the Interior/USGS
These nocturnal water snakes primarily feed on crayfish. They don’t constrict their prey but use their coils to help hold it while swallowing it alive, typically tail-first. Their small, chisel-shaped teeth allow them to consume hard-shelled crayfish.
When disturbed, Glossy Swampsnakes quickly flee into the water and dive to the bottom. If cornered, they may flatten themselves and release a foul-smelling musk from glands near the base of their tail. If picked up, they may hiss and feign striking but rarely bite.
Due to their highly secretive nature, little is known about the population status of these water snakes in Louisiana. But their dependence on aquatic habitats and crayfish may subject them to decline due to habitat loss and degradation.
There are actually two subspecies of Glossy Watersnake that can be found in Louisiana:
- Delta Swampsnake (L. r. deltae): Found in the southeast corner of the state.
- Gulf Swampsnake (L. r. sinicola): Located throughout most of Louisiana.
#10. Eastern Garter Snake
- Thamnophis sirtalis sirtalis
Identifying Characteristics:
- Adults typically range from 18 to 26 inches in length.
- Coloration varies and can be mixtures of green, brown, or black. Look for a distinct yellow or whitish stripe down the center of their back.
- Some individuals may exhibit a checkered body pattern.
- Subspecies of the Common Garter Snake.
Look for these snakes in Louisiana basking in the sun in grassy areas near freshwater.
In fact, they are typically the snake species that people come across the most. They’re well-adapted to living around people and can often be found in city parks, farmland, cemeteries, and suburban lawns and gardens. Though not required, they prefer grassy environments near freshwater sources such as ponds, marshes, lakes, ditches, and streams.
Eastern Garter Snakes protect themselves when they are cornered or feel threatened. For example, if you capture or continually disturb one, it will defecate and release a foul-smelling musk from its glands. It’s also common for them to bite as a last resort!

The Eastern Garter Snake most commonly preys on toads, frogs, slugs, salamanders, fish, and worms. However, they are very opportunistic and will eat other insects and small animals they can overpower. They’re active during both the day and night, depending on the temperature.
#11. Western Ribbon Snake
- Thamnophis proximus
Identifying Characteristics:
- Adults range from 17 to 50 inches in length. A slender snake with a long tail!
- Coloration is blackish, brown, or olive with three light-colored stripes; one down the back and one down each side.
- The sides and top of the head are dark, and the upper lip is whitish.
Did you see a VERY long, slender snake in Louisiana near freshwater?
If so, it was probably a Western Ribbon Snake! This semi-aquatic reptile is rarely found far from a water source. They typically occupy brush-heavy areas around streams, lakes, ponds, and other water bodies. You may also spot them basking on rocks, flat vegetation, and dry sandy areas near water.
The Western Ribbon Snake has an incredible, unique hunting technique. As they move over land, they make quick, light thrusts of their head and upper body in different directions in sequences of three. It’s similar to a strike, but with their mouth closed. This action disturbs resting frogs, which alerts them to their location. From there, this snake uses its superior speed to catch its prey.
When they feel threatened, they flee into the water or hide in thick brush. Their coloration provides superb camouflage in dense, brushier areas. If grabbed, Western Ribbon Snakes rarely bite but will thrash around, defecate, and release musk from their anal glands. This species can also shed its tail to escape, but unfortunately, it doesn’t regenerate like some lizard species.
#12. Red-bellied Mudsnake
-
Farancia abacura
Identifying Characteristics:
- Adults range from 40 to 54 inches in length.
- Coloration is smooth, glossy black with a red and black checkered underside with the red extending up the sides, creating a triangle pattern.
- The chin is heavily marked with black and usually yellow, creating a “zipper-like” appearance.
These semi-aquatic snakes are usually found in Louisiana near stagnant muddy waters of shallow streams, rivers, drainage ditches, canals, lakes, marshes, and swamps. They’re often spotted under water-soaked logs or other wet, organic debris and prefer habitats with dense vegetation and muddy bottoms and banks.
Red-bellied Mudsnakes are specialized hunters! Adult snakes feed almost exclusively on fully aquatic salamanders. They prey primarily on only two species, the Three-toed Amphiuma and the Lesser Siren.
These docile snakes don’t strike when disturbed or captured. Instead, if grabbed, they may press their harmless, blunt tail tip against their attacker, a behavior which has earned them the nicknames “horn snakes” and “stinging snakes” If continually handled, Red-bellied Mudsnakes may release a foul-smelling musk and go limp or play dead.
This water snake is incredibly secretive, and its status is poorly known in many areas.
Do you need additional help identifying a water snake?
Try this field guide!
Which of these water snakes have you seen in Louisiana?
Leave a comment below!