Blotched Water Snakes in Texas 4

— This article by Jerry Cates, Michael Logozar,  Julia E., and Ramona R., first published on 4 April 2010, was last revised on 21 May 2012. © Bugsinthenews Vol. 11:04(02).


Juvenile Blotched Water Snake (Nerodia erythrogaster transversa): Michael Logozar, Round Rock, Texas --- 13 APR 2012

Juvenile Blotched Water Snake (Nerodia erythrogaster transversa): Michael Logozar, Round Rock, Texas — 13 APR 2012

On 13 April 2012, Michael Logozar, of Round Rock, Texas, wrote the following:

Hey, Jerry:

I’m looking forward to the BBQ and seeing you all soon. By the way, I was just now digging around on the Internet, trying to find out what kind of spider I saw this morning, and came across a post where a guy was helping someone identify one. Is that you, Jerry? (He included a link to the post)

Maybe you can help me with my spider, and with two snakes I’ve seen in the last week as well. (He attached photos)

The dark snake I accidentally pulled out of my pool skimmer. It’s some kind of water snake, I guess, and was pretty small, about a foot long. The snake in the grass was probably four feet long, and I’m not sure what it was. And the spider I saw this morning was about two inches in diameter, including the legs.



Juvenile Blotched Water Snake (Nerodia erythrogaster transversa): Mid-body markings; Michael Logozar, Round Rock, Texas --- 13 APR 2012

Mid-body markings

Juvenile Blotched Water Snake (Nerodia erythrogaster transversa); dorsal head: Michael Logozar, Round Rock, Texas --- 13 APR 2012

Dorsal head

Michael Logozar, besides being a world-famous pianist, is also a devoted father of four young children whose home — in Round Rock, Texas — is about a mile from ours. Several years ago, he and our son Andrew worked together in the Information Technology field in Calgary, Canada.

Janet and I recently attended one of Michael’s in-home concerts, where he and two other pianists performed for a sold-out crowd. Once you hear Michael play, you will want to add all his CD releases (click on the link, and go to the store on Michael’s web site) to your music library. Jan and I spend three to six hours or more each day working around the house and in the office with the soothing sounds of his piano playing (click on the videos link on Michael’s website to play a video of Michael at the piano) in the background. His compositions are addictive… in a very good way. Some pianists play, others — like Michael — become one with the instrument, and turn it into a living organism.

We are excited that he and his children will be visiting our humble abode in a few days, when we have our annual spring BBQ bash.

As often happens, good friends of ours who know nothing of my work go searching for information on spiders and snakes and are surprised to find my web pages devoted to those critters. I informed him the long snake in the grass was a Texas rat snake (Elaphe obsoleta lindheimeri), the spider was a wolf spider in the Lycosidae family, and the small dark snake was… well, no need to repeat what this posting is all about.

Notice that Michael’s specimen is darkly patterned, with sharply contrasting markings on a pale background. Another specimen, from Fulshear, Texas, shown below, has identical markings except the background is reddish instead of pale white.


Blotched Water Snake (Nerodia erythrogaster transversa), 040410 Ramona R., Fulshear, Texas--dorsal body

Case history: 4 April 2010: Juvenile Blotched Water Snake (Nerodia erythrogaster transversa), Ramona R., Fulshear, Texas

Ramona wrote (the following is a combination of two e-mails):

Hi. We live in Fulshear, Texas, near Houston.

My daughter found this baby snake dead in our pool. I had just shocked the pool, which is probably what did it in. It’s about 8-10 inches long. Could you please identify it?  I’m having a difficult time doing so…

Also, is this snake venomous?

Thanks so much!


This red-phase juvenile Blotched Water Snake (Nerodia erythrogaster transversa) is not a venomous serpent. At this size, it is also not harmful. Most species of North American water snakes in the genus Nerodia (from the Greek, ναρος [pron. “nay’-ros”] = “flowing, liquid, wet” + δια [pron. “dee’-uh”] = “through,” thus “one who swims in water”)  have a reputation for nasty dispositions, and as they grow larger, their mouths and teeth become correspondingly larger.

Blotched Water Snake (Nerodia erythrogaster transversa), 040410 Ramona R., Fulshear, Texas--lateral head

Blotched Water Snake (Nerodia erythrogaster transversa), 040410 Ramona R., Fulshear, Texas–lateral head

Further, their jaws are relatively strong, so their bites can be painful and bloody. Such bites are not likely to put you in the hospital, but will probably produce lasting memories of the — shall we say — unsavory kind.

A word to the wise, therefore, is to avoid handling mature specimens unless using heavy leather gloves. It is unwise to molest or kill them, however, because despite the liabilities just pointed out, they serve as beneficial members of our environment.

How, you ask?

By, for example, keeping prey populations down, these snakes  compete with venomous snakes, such as Rattlesnakes, Copperheads and Western Cottonmouths. That, in turn, makes the latter less populous as well.

And, for another example, they reduce the toad population so efficiently that we–unlike the inhabitants of Australia (whose introduced cane toad population, absent any native toad predators, has become rather burgeoning)–don’t have to worry about stepping on, or running over, a bunch of bumbling, croaking, humongerous six-pound toads in our yards and on our streets.

Let’s discuss, for a moment, the salient features of the Blotched Water Snake. Notice that the nose is rounded, and that the head seems shaped like a nutmeat, not flat on the top, or with sharp corners or edges to the face. This character grows even more pronounced as the snake ages, until, as a mature specimen, its head will look much like the toe of a comfortable old shoe. I point this out for a special reason: The Western Cottonmouth (Agkistrodon piscivorous leucostoma) has a sharply edged face, with a nose like the prow of a boat, and an unusually flat head.

Now, if you click on the photo of the snake’s head, above, the enlarged image that pops up makes it easier to see the snake’s left eye. Note that it is round, with a perfectly round pupil. This is characteristic of most non-venomous snakes found in North America. In fact, with the exception of the Coral Snake, none of our venomous snakes have perfectly round pupils.

Next, notice the lip scales. Starting at the nose and working backward, along the mouthline, you will find eight upper lip scales. These lip scales are rather large, and–except for the last two–pale in color, with dark margins. Large, pale colored lip scales with dark margins are characteristic of Nerodian water snakes, and help distinguish them from the venomous Western Cottonmouth (Agkistrodon piscivorous leucostoma), whose lip scales are not prominent, either in size or in coloration.

Blotched Water Snake (Nerodia erythrogaster transversa), 040410 Ramona R., Fulshear, Texas--midbody

Blotched Water Snake (Nerodia erythrogaster transversa), 040410 Ramona R., Fulshear, Texas–midbody

The midbody scales show a pattern of lateral bars on the sides that intersect the junctions of the spinal blotches.

The rusty reddish interstices, between the dark bars, will turn grayish as the snake matures.

This is, I suppose, as good a place as any to point out that the species name, erythrogaster, is from the Greek words erythros, “red”, and gaster, “belly”, so this species is a “red-bellied water snake.” But, you protest, its belly is yellowish white.

True, but this is a subspecies, and there exists another subspecies of this species, Nerodia erythrogaster erythrogaster, which really does have a red belly, and is even called the Red-belly Water Snake.  Yet another subspecies happens to have the subspecies name flavigaster, whose prefix is derived from the Latin word, flavus, “yellow”; thus, that subspecies is–you guessed it–the Yellow-bellied subspecies of the Red-bellied Water Snake; its common name is even the Yellow-bellied Water Snake. In other words, the species name of a particular subspecies sometimes, as in this case, has nothing to do with specifics related to the snake, but the subspecies name is generally instructive.

Now, the subspecies that is the subject of this post has the subspecies name transversa, which means “a crossing over”, in reference to the snake’s lateral and spinal markings. Its belly is halfway between pale and yellow, and thus–as with the Yellow-bellied Water Snake–while its species name tells nothing about the belly coloration, the subspecies name tells us something germane.

Got that? If not, no problem… I can go through it again if you wish…

No red belly, but hey, it does have some red on the sides… though not for long. The red portions on the sides of this juvenile are temporary. Eventually all that reddish coloration disappears, leaving the snake’s body a dull gray with pale marks outlining darker bars and spinal blotches. Growing older isn’t all it’s cracked up to be.

Ah, but it beats not growing older. Try to remember that.

The scales are keeled (with median ridges aligned with the long axis of the body) and the keels become more pronounced as the snake matures.


References to Scientific Articles, Papers and Books:

  • Cates, J. 2012. Index to North American Snake Families, Genre, & Species.
  • Conant, R., and J. T. Collins, 1998. Reptiles and Amphibians — Eastern/Central North America, Third Ed. Peterson Field Guides. Houghton Mifflin Co.
  • Greene, H. W., 1997. Snakes: the Evolution of Mystery in Nature. University of California Press.
  • Tennant, A.,1998. A Field Guide to Texas Snakes, Second Ed. Gulf Publishing.
  • Werler, J. E., and J. R. Dixon. 2000. Texas Snakes. University of Texas Press.
  • Wickler, W. 1968. Mimicry in plants and animals. New York: McGraw-Hill.


—  Questions? Corrections? Comments? BUG ME RIGHT NOW! Feel free to e-mail You may also leave a comment in the space provided below.

4 thoughts on “Blotched Water Snakes in Texas

  1. CorySandyNWCO Sep 12,2011 9:37 am

    Ma’am, I am one hundred percent safe with saying the snake is non-venomous. SOURCES-NWCO


    Thank you for this input, Cory.

    Jerry Cates

  2. Elizabeth Mar 16,2013 5:43 pm

    I saw a snake in my pond similar to this. It was probably a foot long or smaller. I wasn’t sure what it was. I didn’t get a good look at it, and Im hoping it wasn’t a moccasin. Are these blotched water snakes in the Galveston/Houston area?

  3. Jim Humphrey Sep 22,2014 8:47 am

    We have a lake place near Ballinger TX we have this snake in our septic & are coming up thru commode into bathroom found two large ones this weekend on wall by shower. Do you know of anything we can put in commode and flush that will get them gone? Thanks

  4. admin Dec 13,2014 11:24 am

    Jim: Unfortunately, most of the repellents you might be tempted to try would not be good for your septic tank. One thing you could try that would make the tank water totally unfriendly to snakes is cayenne pepper. Try pouring 16 ounces of powdered cayenne pepper into the commode, then flush it down. That should keep Nerodia water snakes out of the septic tank for a while. Then let me know how it works.

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