Discover the Largest Salt Marsh Snake Ever Recorded

Written by Jeremiah Wright
Updated: April 8, 2023
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Snakes are fascinating creatures. More than 3,000 species of snakes exist on the planet. Not all of them are venomous or deadly, but 7% of them can kill or severely injure a human. For sure, snakes can either elicit fear or attraction, but never indifference. With the rising environmental issues we face today, many people are paying more attention to wildlife, including snakes. After all, who would not want to know the distinction between a non-venomous snake and a deadly one? Yes, there are docile snakes that would be less likely to bite you during an encounter. 

We introduce you to the salt marsh snake. What are the different types of salt marsh snakes, and where do they live? Read on to discover the largest salt marsh snake ever recorded!

What is a salt marsh snake?

The salt marsh snake is a non-venomous water snake that lives in estuaries.

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The salt marsh snake is a non-venomous water snake living in estuaries. It is the only species of North American snake that lives permanently in brackish water. Like other water snakes, the salt marsh snakes have keeled scales, a divided anal plate, and a reasonably stout body, although thinner than other Nerodia. Different subspecies of salt marsh snakes can be found in coastal Florida, Louisiana, Mississippi, Alabama, Southeast Texas, and North Cuba.

SpeciesNerodia clarkii

Who discovered the salt marsh snake?

American surveyor John Henry Clark found the salt marsh snake when he conducted the Texas Boundary Survey in 1860. The species name Clarkii was named after him.

What is the size of the largest salt marsh snake?

The largest salt marsh snake has a total length of 36.7 inches.

©Jay Ondreicka/

In 2004, Gibbons and Dorcas recorded the largest salt marsh snake (Nerodia Clarkii) with a total length of 36.7 inches (93.3 cm). 

What are the different types of salt marsh snakes?

Salt marsh snakes, scientifically named Nerodia clarkii, have three subspecies: Gulf salt marsh snake (Nerodia clarkii clarkii), Mangrove salt marsh snake (Nerodia clarkii compressicauda), and Atlantic Salt Marsh Snake (Nerodia clarkii taeniata). Each species inhabits different types of water bodies, just as their common name indicates. 

1. Gulf salt marsh snake (Nerodia clarkii clarkii)

Gulf Salt Marsh Snake

Gulf salt marsh snakes can grow up to 15 to 30 inches.

©Jay Ondreicka/

Gulf salt marsh snakes, scientifically known as Nerodia clarkii clarkii, are flat-headed, non-venomous snakes that thrive in estuaries, where salt water meets fresh water, resulting in brackish water. They can be found along the Gulf Coast of the United States, especially in coastal Texas and Alabama. Texas Wildlife Conservation says they can grow up to 15 to 30 inches (38 to 76 cm). Their dorsal (top or back posterior) has yellow or tan stripes, while their ventral (bottom or front side) is grayish-black or reddish-brown. Some have one to three pale spots on their bellies.

The largest recorded adult specimen of Gulf salt marsh water (Nerodia clarkii clarkii) is measured at 36 inches (91.4 cm) long. Most adult species only grow up to approximately 24 to 30 inches (60 to 76.2 cm) long.

2. Mangrove salt marsh snake (Nerodia clarkii compressicauda)

Mangrove salt marsh snakes are non-venomous snakes that live in estuarine mangrove forests dominated by red mangroves.

© Strasser

Mangrove salt marsh snakes, scientifically called Nerodia clarkii compressicauda, are non-venomous snakes that live in estuarine mangrove forests dominated by red mangroves. They can be found in southern Florida, especially Tampa Bay, the Florida Keys, and the northern coast of Cuba.

The colors of mangrove salt marsh snakes are highly variable, but the most common is the “green morph,” which has dark olive green with brown bandings. “Red morphs” are rare but are observed to have a rustic-red color with alternating light and dark bandings or are uniformly a dark reddish-orange.

According to research, an adult Nerodia clarkii compressicauda can range from 15 to 30 inches (38 to 76 cm) when measured from snout to vent.

3. Atlantic salt marsh snake (Nerodia clarkii taeniata)

Atlantic salt marsh snakes are about 24 inches long.

©Fine Art Photos/

Atlantic salt marsh snakes, scientifically named Nerodia clarkii taeniata, are also non-venomous snakes. They are slender, heavily keeled (21-23 rows of keeled scales), and are about 24 inches (61 cm) long. Their dorsal color is pale olive with dark brown stripes, while their ventral has rows of dark blotches that integrate to form stripes in the neck region. The federal status of Atlantic saltwater marsh snakes is threatened. True to its name, Atlantic salt marsh water can inhabit salt marshes and mangrove swamps that vary in salinity from brackish to full-strength saltwater. They can be found along tidal creeks, ditches, and pools in  Volusian Country, Indian River County, and Florida’s Atlantic Coast.

Is a marsh snake venomous?

Salt marsh snakes are non-venomous. They usually stay still to avoid detection, but when approached, they will flee. They are quiet and not aggressive compared to other species of water snakes. According to academic research, salt marsh snakes don’t usually bite and musk as much as large Nerodia species when caught.

What do salt marsh snakes eat?

Salt marsh snakes eat small fishes, crabs, and shrimps. Sometimes they would eat tiny frogs too. They are nocturnal, so they hunt for food at night, usually when it’s low tide. They are not constrictors, so they eat their prey by attacking with their jaws and swallowing it alive. 

Other Record-Breaking Snakes

green anaconda

Green anaconda can reach 25 feet long!

©Patrick K. Campbell/

Snakes have been known to set records for size and length, as well as other feats. While the longest snake ever recorded was a reticulated python measuring 32 feet 8 inches long, there are many other huge snakes that have been caught or seen in the wild. The largest anaconda on record measured 29 feet 5 inches and weighed 213 pounds.

Burmese pythons, green anacondas, African rock pythons, and Indian pythons are some of the other large snakes found in nature. The Burmese python is known to grow as long as 20 feet, while the Green Anaconda has been recorded at 25 feet 4 inches. In comparison, the African Rock Python can reach lengths of 21 feet, and Indian Pythons have an average length of 18 feet when fully grown. All these species have unique characteristics that make them distinct from each other, but they all belong to the same animal family – Pythonidae.

In addition to setting records for size, some species of snakes also display remarkable agility and speed on land. The fastest snake is believed to be the black mamba which can reach speeds up to 12 miles per hour over short distances!

The photo featured at the top of this post is © Jay Ondreicka/

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About the Author

I hold seven years of professional experience in the content world, focusing on nature, and wildlife. Asides from writing, I enjoy surfing the internet and listening to music.

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