Tag Archives: sea snakes

A Partial Answer To Gulf Sea Snake Mystery

The réponse to my blogs about sea snake sightings in the Gulf of Mexico has been tremendous. I have received nearly 200 reports dating back to the 1970s ranging from Cuba to the South Texas Coast.

Some have included photos that were misidentified eels, yet other reports were more mysterious.

Sea snakes are not indigenous to the Gulf of Mexico or Atlantic so these reports are quite controversial to say the least.

I recently received an email with an interesting and (fairly) clear photo of a snake caught on Galveston Island, TX.

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A Gulf salt marsh snake caught on Galveston Island in Texas. (Photo submitted by Ashley Moore)

The people who caught it thought it might be a sea snake.

After all, it was on the beach and did not look like snakes commonly seen by most citizens in the region.

The snake in the photo however is a Gulf salt marsh snake (Nerodia clarkii clarkii).

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Naturalist and wildlife photographer Cody Conway was kind enough to let us use this photo of a Gulf salt marsh snake he photographed on the Texas coast. Conway noted there is some hybridization among the nerodia snakes in the region and some variation in patterns in salt marsh snakes. (Photo by Cody Conway)

I never thought of these being the source of some Gulf region sea snake sightings until receiving this photo.

It does makes sense for numerous reports I have received in open bays and beaches in the region.

Very few people know of this snake and they are very aquatic.

According to officials with the Texas Parks & Wildlife Department (TPWD), the Gulf salt marsh snake grows to a length of 15 to 30 inches.

Distinguishing characteristics include two longitudinal tan or yellow stripes on each side of the body, making up the dorsal (top) pattern of the snake. It has a reddish-brown or grayish-black ventral (bottom) color with one to three rows of large pale spots along the center of the belly. This snake is flat headed.

They added that as a way to avoid predators, salt marsh snakes are nocturnal (active at night) and often hide in shoreline debris and in crab burrows in the mud or sand.

The Gulf salt marsh snake does not have salt glands to help rid itself of the salt it eats so it must be very careful not to drink salt water. It gets moisture from rainfall and from the animals it eats.

Interestingly, their name is Nerodia clarkii, but it is a subspecies of this group so the actual name is Nerodia clarkii clarkii according to the University of Florida 

The other two subspecies are found in Florida.  The Mangrove salt marsh snake (Nerodia clarkii compressicauda) is found from central Gulf coast of Florida, around the Keys to Indian River County on the Atlantic coast.  The Atlantic salt marsh snake (Nerodia clarkii taeniata) has a very small range.

These snakes are nonvenomous but will bite if handled.

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An illustration of a true sea snake, a banded sea krait. If you are vacationing or working in their Pacific and Indian ocean range do not pick up. Sea snakes are the most venomous snakes on Earth despite generally having a calm disposition.

It’s best to leave them alone especially noting that TPWD officials and other researchers believe their numbers are on the decline.

These unique snakes will not account for all of the “sea snake”sightings in the Gulf region but I now believe they are part of the equation.

Chester Moore, Jr.