Tennessee is not known for its abundant aquatic environment, however, 50,000 miles of rivers and streams, and about 500,000 acres of lakes, ponds, and marshes make it a haven for both aquatic and semi-aquatic snakes. While many of Tennessee’s water snakes are not poisonous, it’s always wise to be cautious concerning snakes.
This article will list several types of water snakes in Tennessee. Included here you will find descriptions including size, habitat prey, habits, coloring, features, and other helpful information. As you will read, many or most of the aquatic or water snakes indigenous to the state of Tennessee are non-venomous.
Keep in mind just because a snake is non-venomous does not mean it is harmless to humans or that it will not bite. Snakes in their natural habitat should be left alone.
This list contains likely not every species of aquatic or water snake or semi-aquatic snake that can be found in the state of Tennessee. It is a compilation of the most frequently encountered water snakes known in the state.
1. Mississippi green water snake
The Mississippi green water snake (Nerodia cyclopion) is not venomous and grows on average to about 30-45 inches long. These dark greenish-brown snakes hunt fish and frogs. They have distinctive, half-moon-shaped yellow markings on their bellies. The Mississippi green water snake lives in the swamps of most western parts of Tennessee.
Quick Fact: The Mississippi green water snake is typically identified by a row of scales between the eyes and lips.
2. Plain-Bellied water snake
The Plain-Bellied water snake (Nerodia erythrogaster) also known as the yellow-bellied water snake is another non-venomous water snake in Tennessee. They can grow to an average of 30-40 inches long. Plain-bellied water snakes are found in the south-central and southwestern parts of Tennessee.
These guys are black on top with pale yellow or brown bellies, hence their common nickname yellow-bellied water snakes. They prefer lakes and swamps over rivers. The diet of the yellow-bellied snakes consists of frogs, lizards, and tadpoles or small fish, and the like. Depending on their size, these snakes may be eaten by other snakes or birds.
3. Southern Water snake
Another water snake in Tennessee is the Southern Water snake (Nerodia fasciata). On the smaller size. These snakes grow to an average of 22-36 inches and are non-venomous. The southern water snake has bands of dark and lighter browns on their backs.
This makes them easy to confuse with the Cottonmouth, a venomous water snake found in Tennessee, which we will learn about further in this article. These guys live in counties bordering the Tennessee River and live on mostly fish.
It is convenient to know that a faint black line runs from the corner of the eye diagonally to the corner of the mouth while the Cottonmouth has a distinctive facial pit between the eye and the nostril. Another tip about these snakes is that they frequently can be found actually hanging out on branches overhanging the water.
4. Diamondback water snakes
Diamondback water snakes (Nerodia rhombifer) not to be confused with the diamondback rattlesnake) are found in western and middle Tennessee. They average about 30-48 inches long when grown and are also non-venomous snakes. They can live in any aquatic habitat but tend to prefer rivers and swamps.
They have markings on their backs that create the diamond shape they are named for. The pattern resembles netting stretching across their backs. The adult males of this species have multiple papillae (tubercles) on the undersurface of the chin. These are not found on any other species of snake in the United States.
Diamondback water snakes like to eat slow-moving fish like catfish. These guys become primarily nocturnal during warmer months and are more active during the day by winter.
5. Northern water snake
Next up we have the Northern water snake (Nerodia sipedon) which averages about 24-42 inches long. These snakes are non-venomous and tend to have more color variation than most snakes, ranging from grays to browns, and even black sometimes. This snake tends to live throughout the state of Tennessee, preferring quieter waters like ponds and lakes.
They like to fish and frogs and such for breakfast, lunch, or dinner. These guys typically run from danger, but become aggressive and bite repeatedly when captured. The Northern water snake is also easily mistaken for the venomous Cottonmouth, another water snake we will talk about further in this article.
Expert Tip: Just remember the cotton mouth has a facial pit between the eye and nostril when trying to identify it from similar-looking aquatic snakes.
6. Western ribbon snakes
Western ribbon snakes (Thamnophis proximus proximus) are smaller water snakes averaging 20-30 inches in length. These non-venomous snakes can be identified by the stripes running down their backs. Their ground color is black with white or mint green skin between the scales.
The stripes running down their backs usually are usually as follows: the dorsal stripe is orange, and lateral stripes are cream to yellow. The ribbon snake can spend time on land as often as in the water. However, they are only found in the westernmost part of Tennessee. Eating tadpoles and minnows, these guys are very quick, and they typically run from danger.
These snakes are harmless to humans. The western ribbon snake is likely the most aquatic of all garter snakes. When captured they expel a musk and thrash wildly. Much less likely to bite than other snakes of similar species.
7. Eastern ribbon snakes
We cannot forget about the Eastern ribbon snakes (Thamnophis sauritus) which are just as small at 18-26 inches on average. Not to be confused with the name of these snakes, they are found in the western parts of the state. Eastern ribbon snakes are easily identifiable by three yellow stripes running down their backs.
They are generally more slender than snakes of similar species. These ribbon snakes spend less time actually in the water, however preferring stay very near it on the heavily vegetated banks of the rivers and streams. These guys glide easily across the top of the water when fleeing danger.
Quick Fact: The Eastern ribbon snake survives by feeding on small fish and amphibians. These ribbon snakes can be found swimming in water swimming very near the shoreline.
8. Common Garter Snake
Now let’s talk about the Common Garter Snake (Thamnophis sirtalis) which is closely related to the ribbon snakes. These smaller fellows average about 18-26 inches in length. They are distinguished from the ribbon snakes by their lighter, spotted coloration. The garter snakes are found throughout the state of Tennessee.
They like to live nearest the pond, in wetlands. The Garter snake is known as the fastest snake in Tennessee have a diet consisting of frogs, fish, and even earthworms. The common garter snake is the most defensive among the garter snake species.
Like the Eastern and western ribbon snakes, these snakes will struggle and thrash if captured. Also secreting a foul-smelling discharge as a defense mechanism.
9. Queen snake
The Queen snake (Regina septemvittata) likes to live in and around running water like streams and rivers, but it can be found in lakes as well. They grow to an average length of 24 inches. This snake is non-venomous and is generally grayish in color with three darker lines running down its back.
The belly tends to be yellowish and can also have stripes. Queen snakes like to eat crayfish which is why they like Tennessee’s creeks and rivers. They can often be found in rocky habitats and aren’t very shy often times visible basking in sunlight upon rocks in the streams and rivers.
10. Cottonmouth snake
Lastly, I’d like to mention the Cottonmouth snake (Agkistodon piscivorus) also known commonly in Tennessee as the water moccasin. This is probably the most well-known water snake in Tennessee. The cottonmouth is likely ranked the most dangerous water snake in Tennessee as well. They are a type of pit viper.
They are most definitely venomous and have a nasty reputation for being aggressive. When threatened they hiss loudly and open their mouth displaying the bright white inside (hence the name cottonmouth) as a show of threat and danger. These scan snakes have very thick-looking bodies with dark brownish coloration.
They also have a large triangular-shaped head. The cottonmouth snake isn’t nearly as aggressive as reputation would have you believe but is definitely a snake you should avoid. Stories would have us believe these snakes will chase people but in reality, they tend to hide from danger. A bigger snake for sure averaging around 30-42 inches in length.
Cottonmouth snakes prefer to inhabit swamps and wetlands. These larger snakes like to eat small mammals, turtles, birds, and even other smaller snakes. Cottonmouth snakes are typically the least common, with rare sightings in the Cumberland River Basin. They are probably the most physically intimidating of snakes in Tennessee aquatic and not.
You will definitely not question the cottonmouth’s identity if you happen to find yourself too close to one.
Conclusion
Tennessee is home to many species of snakes aquatic and not. It is wise to be educated on snakes in your area. As we have learned in this article, most of the aquatic or water snakes in Tennessee are non-venomous. Snakes typically run from danger but it is still wise to leave them to their own business if you happen upon one.
Just because a snake is non-venomous doesn’t mean a bite is not painful. Snakes tend to remain in their own habitats and play their part in the food chain. It is always a good idea to keep an eye out in heavily vegetated or very rocky areas, as we have discussed places like these are where snakes like to stay.
The Tennessee Wildlife Resource Agency has identified 32 species of snakes native to the state. Only three of those are venomous and only one of said venomous snakes is an aquatic or water snake (that scary pit viper, the Cottonmouth, or water moccasin).
With the destruction of habitats, killing of their prey, and killing them due to misplaced fear, people present a far greater threat to snakes than they do us, one important thing to remember if you encounter a snake of any kind, is to leave it be for the sake of snakes and yourself alike, take those words into Tennessee wild with you. Leave It Be!
Any questions or comments are most welcome in the comment section of this article. There are most definitely several species of aquatic or water snakes in the state of Tennessee and its neighboring states. There is however only one species of water snake that is venomous in the state of Tennessee.
That is not to say, however, that water snakes in other states are mostly non-venomous. This article discusses the water snakes in Tennessee only. Again, feel free to place any questions in the comments about Water Snakes of Tennessee.