Snake I.D. – Louisiana’s snakes identified Part III: Watersnakes

(Photo by CJ Hillard)

There you are at your sweetest fishing hole. You’re surrounded by the beautiful swampy terrain of the Louisiana landscape, with cypress trees and palmetto leaves as far as your eyes can see.

You’ve been here before, but this time, something is different. Nearby there is a rustling sound among the leaves and water. To your startled surprise there is a 4-foot snake slithering right past you, about to snag your most recent catch for his dinner!

You fear the worst and send pictures to a few friends, all of whom swear it has to be a cottonmouth, a copperhead or something most definitely terrible for this reason or that. You then remember that Louisiana Snake ID can identify it for you, so you send a message to that Facebook page. You’ll get a response in a few minutes and learn it is merely a harmless diamond-backed watersnake. Your fears are calmed, and you go ahead and let him have that little guy you weren’t going to keep anyway. He’s full and happy, and you’ve made a new friend.

This story, or some variation of it, happens to us at Louisiana Snake ID on a daily basis — exactly what we’re here for. We are excited to share a little more information about snakes native to Louisiana. You can read about the difference between constrictors and live eaters in our previous articles (Snakes Part I, Snakes Part II) and Venomous snakes). All of the snakes listed in this one are live eaters and therefore, do not kill their prey before eating it. Over the past few months, we’ve covered slightly more than half of the 48 species found in our wonderful state. Now let’s take a look at six more.


All of these snakes are in the Nerodia genus and are commonly known as watersnakes. These are non-venomous, semi-aquatic snakes. They all have a very similar diet, so I will mention that here rather than in each description. Their prey consists of cold-blooded, primarily aquatic animals. Watersnakes love to eat various species of small fish, minnows and amphibians, including tadpoles, frogs or salamanders. Just like us, they will from time to time enjoy a crawfish. Being exceptional climbers, they are often found lounging on a log or tree limb and will even hang off a limb with their head submerged, waiting for an unsuspecting fish or frog to swim close enough to bite. Contrary to popular belief, water moccasins are not good climbers and are very rarely found lounging up in a tree, so if you have a snake fall into your boat, it’s most likely a harmless watersnake.

These snakes have highly keeled scales, meaning that they feel rough to the touch. They occur throughout the state, and they typically live around ponds, lakes and wetlands, but they are known to venture away from water in search of their main prey: frogs. If threatened, they often secrete a foul-smelling liquid comprised of digestive system by-products called “musk” — it smells very similar to a skunk!

Multiple indicators

It’s important to use more than one indicator when trying to determine whether or not a snake is harmless from a safe distance. This is definitely true with the many color variations that are possible among watersnakes. Their best individual indicators are the dark vertical lines/stripes along the side of the mouth. The actual color of these lines can vary from black to dark green to brownish-green, but they will be darker than the lighter color of their jaw line and chin area. Since there is a chance that you could find yourself looking down at the snake from the top and you can’t see the side of its mouth, if the eyeballs are visible from the top of the head, you can know you’re not dealing with a venomous pit viper like a water moccasin, copperhead or rattlesnake. Remembering, this is also very helpful because watersnakes are notorious for flattening their heads and bodies to look more dangerous. Often, this gets them killed due to misinformation. Our goal is to minimize the chances of that happening. Not all non-venomous snakes have these lines, but if you see them on a snake in the United States, then it is non-venomous.

The following species are among the most commonly found snakes in Louisiana especially for anyone who spends time around the water while hunting, fishing or just enjoying nature. There are easy ways to recognize them, but remember, that individual snake patterns and colors can vary.

Common Watersnake (Nerodia sipedon)

(Photo by CJ Hillard)

The only subspecies of common watersnake that exists in Louisiana is the midland watersnake, Nerodia sipedon pleuralis. These snakes have a light tan or grey color with red or brown bands that are thin near the belly and wider near the spine. The bands connect with saddle shapes near the head but become distinct bands and saddles about a third of the way down the body. Their bellies are mostly white, with small red or black triangle markings arranged in groups that look kind of like Christmas trees, and they typically become more dense near the tail. These snakes average 2 to 31/2 feet long, with a record of 59 inches, and spend their lives primarily around some kind of water source. While often confused with water moccasins, these guys don’t actually look very much like their venomous “counterparts.” They have been found primarily in the Florida parishes with an isolated sighting in Ouachita Parish.

Southern Watersnake (Nerodia fasciata)

(Photo by Kyler Hood)

The only subspecies of southern watersnake in Louisiana is the broad-banded watersnake, Nerodia fasciata confluens. Averaging 2 to 31/2 feet long, with a record of 621/2 inches., these gorgeous snakes are found across almost the entire state of Louisiana. They vary in coloration more than any other watersnake species, from nearly completely black to light grayish/brown with broad bands, to even brightly orange colored on occasion. The bellies of these snakes are vividly colored in bright reds, oranges and maroons and are my favorite thing about these amazing snakes. Since they vary so much in color, these harmless snakes are often mistaken for both venomous cottonmouth water moccasins and also venomous copperheads.

Diamond-backed watersnake (Nerodia rhombifer)

(Photo by Kyler Hood)

These harmless snakes are green to brownish-green in color and have a darker distinct “chain link” pattern along their backs. As the largest species of North American watersnakes, they average 3 to 4 feet long with a record of 69 inches. They are the most likely to flatten their head into a “diamond-shape” when threatened, and their size makes this defense mechanism more noticeable as compared to the other species listed. These curious snakes have been known to approach a fisherman hoping for an easy meal. Diamond-backed watersnakes use their size to their advantage by eating larger fish and frogs than most of the other watersnake species and are often spotted by docks and boat launches eating fish, even catfish. They’re found across the entire state, yet many are unfortunately killed because people assume that any snake found near the water is a “water moccasin.”

Plain-bellied watersnake (Nerodia erythrogaster)

Plain-bellied juvenile (Photo by Kyler Hood)
Plain-bellied adult (Photo by Kyler Hood)

Adults are a solid black or grey color. Their bellies are white or yellow with no physical markings, hence the name “Plain-bellied” watersnake. These snakes average between 3 to 4 feet with a record size of 64 inches. Juveniles have unique patterns down their backs. Their pattern consists of bands on the side of the body that connect with the saddles on their backs near the head but will become disconnected bands and saddles further down the body.

Mississippi Green watersnake (Nerodia cyclopion)

(Photo by CJ Hillard)

These snakes are typically a dark or olive green color with dark bands on the side of the body that don’t reach the back. The larger ones often become too dark to notice any pattern, but their bellies are quite unique; they are light yellow with no markings near the head. Near the middle of the body, the color becomes a dark brown or reddish color with light markings that resemble “half-moons” or semi circles. Mississippi greens reach around 3 feet with the record of 51 inches. This species is found throughout south Louisiana, excluding much of the coast. They also occur along the Mississippi delta. They are not known to occur in central or west Louisiana or in the Florida parishes. They typically occupy larger bodies of water such as creeks, rivers, lakes, and large ponds where they prey on fish almost exclusively.

Saltmarsh watersnake (Nerodia clarkii)

(Photo by Elizabeth Henry)

These tend to be a little smaller than the other watersnake species. They are most often black with two yellow or orange stripes that run the length of the body. Sometimes, there are disconnected spots, instead of stripes, that run the length of the body. Their bellies are also black, with a single row of yellow or red triangles, and the dark vertical lines on their jaws aren’t typically quite as obvious as in other species. Like all watersnakes, these also have keeled scales that will make them feel rough to the touch. They’ll usually reach around 2 feet long, with a record length of slightly more than 3 feet. Unlike any other snake in Louisiana, this species is only found in the brackish and saltwaters of the coast where they feed almost exclusively on fish, but will snag a small crab now and then. They are not typically found more than a few miles inland.

Thanks for taking the time to learn important facts about snakes any of us could encounter during almost any outdoor activity in Louisiana.

Don’t forget to check out Louisiana Snake ID Facebook page for lots of snake facts and fun. They can also be found at LA Snake Boyz on YouTube and Snake education is their passion!

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