Discover the Largest Black Swamp Snake Ever Recorded

North Florida Swamp Snake

Written by Taiwo Victor

Updated: September 15, 2023

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The black swamp snake is a small, aquatic, non-venomous snake native to the Eastern United States and the coastal areas of Southeastern Canada. The word pygaea in its scientific name Liodytes pygaea is derived from the Greek meaning “fire-like,” possibly referring to their unique color. At 10 to 15 inches, this black snake is tiny in size, and its color allows it to blend easily with its surroundings. But how big do these little slithering creatures get? What is the largest black swamp snake ever found? 

Background on the Black Swamp Snake

The black swamp snake is a species of snake in the subfamily Natricinae of the family Colubridae. This species is endemic to the Southeastern United States. Three subspecies are recognized as valid; South Florida swamp snake (Liodytes pygaea cycles), North Florida swamp snake (Liodytes pygaea pygaea), and Carolina swamp snake (Liodytes pygaea paludis).

What Does the Black Swamp Snake Look Like?

Seminatrix pygaea

The scales on the body of a black swamp snake are smooth.

©Dawson / Creative Commons – Original / License

The black swamp snake is a small snake that is grossly shiny black on the dorsum and has a bright red or orange belly with black markings on the edges. The scales on the body are smooth. The head is about the same size as the neck. The black swamp snake is a fairly small, thin, and adult species that measures approximately 10 to 15 inches. Newborns have a total length of roughly 11–14 cm (4¼-5⅜ in), and their coloration is similar to miniature adults. Females are much longer and heavier-bodied, but males have longer and thicker tails. 

Because swamp snakes are aquatic snakes, they may be confused with similar small mud snakes. But to differentiate them, note that mud snakes have red coloration that extends to their sides and a black checkerboard pattern on their belly. Black swamp snakes can also be confused with terrestrial red-bellied black snakes because they have similar red/orange belly patterns. However, the solid black dorsal coloration and aquatic habits of swamp snakes distinguish them from terrestrial red-bellied snakes. 

Largest Black Swamp Snake Ever Found 

North Florida Swamp Snake

The largest black swamp snake recorded measured 24.5 inches in length.


Black swamp snakes are fairly small-sized. They are usually 25–38 cm (10–15 in) long (including the tail). Large swamp snakes measuring about 55 cm (22 in) have been reported. The largest black swamp snake ever found measured 24.5 inches (62.2cm) long. 

The Behavior of the Black Swamp Snake

As its name suggests, the black swamp snake is almost entirely an aquatic species. Within the water, it is active both during the day and at night. It spends most of its life hiding among dense aquatic vegetation, especially in swamps, where it actively forages amidst submerged vegetation. Though their black appearance suggests otherwise, they are generally harmless, even when restrained. However, they may release musk from glands at the base of their tail when captured; they rarely bite in defense.

How Do Black Swamp Snakes Reproduce? 

Breeding season for this species starts from August through October. The black swamp snake is ovoviviparous, meaning the females give birth to live young ones (about 11 to 13) directly in shallow water. Unlike many other snake species, females feed actively while gravid, suggesting they may pass nutrients to the young. 

These reptiles have quite a list of predators. The most common foes they must look out for are egrets and herons.

Black Swamp Snakes: Range

The black swamp snake is widely distributed across South Carolina, North Carolina, Georgia, Florida, and Alabama. Its range extends from the Coastal Plain of the southeastern United States from eastern North Carolina west to southern Alabama and Florida, extending up to 150 to 180 km (93 to 112 miles) inland from Georgia and South Carolina coasts. 

Where Do Swamp Snakes Live?

Black swamp snakes occupy various open aquatic habitats, including swampy areas,  marshes, sphagnum bogs, bay heads, Carolina bays, wet grassy prairies, and roadside ditches. They’ve also been found to inhabit the borders of heavily vegetated wetlands, ponds, and lakes.

Black swamp snakes are docile and extremely secretive. Even though they are abundant in some habitats, they are rarely seen, even by experienced herpetologists. These shy little snakes prefer to hide among vegetation in water or under debris at the water’s edge, particularly on sunny spring days. But occasionally, this species has been found crossing roads during summer after heavy rainy nights. They may also travel on land when pond basins dry up. 

What Do Black Swamp Snakes Eat?

Swimming tadpoles

Tadpoles are a regular part of a black swamp snake’s diet.

©Joshua Ouellette/

Black swamp snakes feed on aquatic prey, including tadpoles, small fish, frogs, sirens, salamanders, and invertebrates, such as earthworms and leeches. They are sit-and-wait ambush predators known to swallow their prey alive without first constricting them. 

What Eats Black Swamp Snakes?

Grey heron in flight

Herons, egrets, and large fish are rather fond of dining on black swamp snakes

©Adrian Eugen Ciobaniuc/

These reptiles contend with quite a range of predators. The most common foes they must look out for are egrets and herons which are not above wading through their habitat in search of a tasty morsel. Fish, especially those that happen to be large in size, can constitute a danger to their well-being and bass have been known to help themselves to these reptiles who prefer to live in the water or close to it.

How Dangerous Are Black Swamp Snakes?

Black Swampsnake

The black swamp snake is non-venomous and is not a danger to people or pets.

©Peter Paplanus / flickr – Original / License

The black swamp snake is a non-venomous species and is not dangerous to people or pets. When threatened, these docile snakes typically do not bite in defense; instead, they attempt to escape quickly. Because they live under submerged vegetation, people sometimes step on this snake which could cause it to be forced to bite in self-defense. Though they do not have venom glands in their mouth, direct handling should also be avoided as a bite may cause mild reactions ranging from itching and swelling to nausea and dizziness. 

How Long Do Black Swamp Snakes Live?

Black swamp snakes have an average lifespan of about seven years when left in the wild. However, they can live up to about 20 years when in captivity.  Its lifespan in the wild is comparable to species such as corn snakes and garter snakes which are known to live for similar lengths of the time in wild as well.

It is however outstripped in this regard by several species including eastern diamondback rattlesnakes which have been known to live for 25 years in captivity, as well as copperheads and eastern indigo snakes which have also been known to reach the same number of years under expert care.

Conservation Status of the Black Swamp Snake

Black swamp snakes are listed as “Least Concern” on the IUCN Red List of Threatened Species. Their population is relatively stable. However, little is known about this species’ status in most areas because of its secretive and highly aquatic habits. They also rely heavily on fishless wetlands, making them vulnerable to habitat destruction. For this reason, this species is of conservation concern throughout its range. They are protected throughout states such as Georgia. 

Other Record-Breaking Snakes

Green Water Snake

Mississippi green water snakes are semi-aquatic snakes found in Mississippi, Alabama, Kentucky, and Louisiana.

©Rusty Dodson/

After reading about the largest black swamp snake – you may want to turn your attention to another semi-aquatic snake of the south – the largest Mississippi green water snake. Green water snakes are among the most common snakes found in Mississippi and in Alabama, Kentucky, and Louisiana. These water-loving reptiles live in cypress swamps and in the Mississippi lowlands and grow up to 45 inches or longer. This non-venomous snake has a thick, medium-sized body in a dark green color – mostly olive with numerous faint, olive-brown, or dark-brown patterns that alternate down its back and flanks.

Green water snakes are non-venomous and are not constrictors, so they ambush their prey quickly and eat them while they are still alive. They are semi-aquatic – with a diet consisting of frogs, salamanders, toads, minnows, crayfish, small rodents, and other reptiles. How big is the largest Mississippi green water snake ever recorded? It’s over 45 inches long! Read the next post to find out the exact length and more information about this fascinating snake.

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About the Author

For six years, I have worked as a professional writer and editor for books, blogs, and websites, with a particular focus on animals, tech, and finance. When I'm not working, I enjoy playing video games with friends.

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