A Diamond-backed Water Snake in Bullard, Texas

This article by Jerry Cates and John Wise, first published on 1 March 2010, was last revised jon 23 April 2016. © Bugsinthenews Vol. 11:03(05).


Diamond-backed Water Snake (Nerodia rhombifer rhombifer): Dorsal head & anterior body; John Wise, Bullard, TX --- 14 Apr 2012

Diamond-backed Water Snake (Nerodia rhombifer rhombifer): Dorsal head & anterior body; John Wise, Bullard, TX — 14 Apr 2012

John wrote on 14 April 2012:

Hello sir, my neighbor killed this snake in backyard in Bullard, Texas, some twelve miles south of Tyler. Could you tell me what type of snake this is ?

I replied that this was a diamond-backed water snake (Nerodia rhombifer rhombifer), and that some of my old articles on the species are posted at

Click on any of those links to visit the pages they refer to. For camera buffs John’s photos were taken with a Nikon Coolpix P100. The photo above was shot with a shutter speed of 10/1340 sec., at f4.5, a focal length of 23mm, and without using flash.

Diamond-backed Water Snake (Nerodia rhombifer rhombifer): Dorsal head & anterior body; John Wise, Bullard, TX --- 14 Apr 2012

Dorsal head

Diamond-backed Water Snake (Nerodia rhombifer rhombifer): Dorsal mid-body; John Wise, Bullard, TX --- 14 Apr 2012

Dorsal mid-body

The linked articles above are on my original bugsinthenews website, which is in the process of being updated and moved — albeit slowly — to this site. John sent a second photo showing the unsullied mid-body markings, and because his images are of good quality I decided to post them here, on a new page. One of these days I’ll move the content of those old pages over here too.

Hopefully John can shoot photos of the tail and belly, including the vent. If so, I’ll post them as soon as they come in.

The etymology of the generic name, Nerodia, is described elsewhere. The specific and subspecies names are the same, indicating this is considered the type-species; two Mexican subspecies, N. rhombifer werleri, and N. rhombifer blanchardi, respectively known locally as Tabasco and Tampico Diamond-backed water snakes, are found in northeast Mexico (The Mexican state of Tamaulipas: city of Tampico) and south along the Mexican Gulf and Atlantic coast (The Mexican state of Tabasco). The name rhombifer was assigned by the American herpetologist and physician Edward Hallowell (1808-1860) in 1852 when he first described the type species, and is derived from the Greek word ρομβος “rhombus” = a lozenge, i.e., a diamond-shaped article or marking. This obviously is a reference to the markings on the dorsal surface of this serpent, though, since today the word “lozenge” is not commonly spoken, we are more inclined to describe this pattern as that of a chain-link fence. In ancient times, things were different: lozenge patterns date from the Neolithic and Paleolithic periods of Eastern Europe, when they were variously used to represent sown fields and feminine fertility. The same patterns often show up in Diamond vault architecture, in traditional patterns adorning Slavic dress, in the traditional embroidery of the Ukraine, and in Celtic, Ottoman, and Phrygian art.

Thus, the specific name for this serpent was well chosen.

John’s specimen, from a location near Bullard, Texas, appears to be an adolescent. He did not mention the length of the snake, but authorities report the average mature snake measures 20-34 (Tennant, 1998) or 30-48 inches in length (Conant & Collins, 1998; Werler & Dixon, 2000), with a maximum recorded length of just over 60 (Tennant, 1998), 63 (Conant & Collins, 1998), or 68.33 inches (Werler & Dixon, 2000, citing a report by Betz, in 1963). In any case — because the markings on this snake are rather well delineated — it is not close to maturation as, in older specimens, the markings become muted, eventually to the point they are impossible to make out.

Werler & Dixon (2000) point out that a partial cause of the muted markings on older specimens involves the action of thin films of algae and silt, which obscure the scale patterns when these serpents have lived for long periods in murky water. The venomous cottonmouth, like the diamond-backed water snake, darkens with maturity to the point that it’s markings become indistinguishable. However — while some other nerodian water snakes resemble the cottonmouth in color pattern and may be mimics of it (Greene, 1997, p.200) — the diamond-backed water snake bears little actual resemblance and, as noted below, experienced herpers quickly tell the difference between the non-dangerous diamond-backed water snake and the venomous cottonmouth:

Note the keels on the scales of this fellow. Most body scales have a raised longitudinal ridge running down the scale’s median. As the snake matures the keels become more pronounced, to the point that very old specimens look alligator-like in appearance. This tends to cause observers to conclude that they are looking at a venomous cottonmouth (presuming, incorrectly that the cottonmouth would have a rough, alligator-like skin) when, in fact, the cottonmouth has smooth to weakly-keeled scales that never approach the appearance of an alligator.

Females tend to be larger than males (Greene, 1997, p. 60), while the males can be distinguished by the presence of chin tubercles (ibid, p. 124). Mating occurs, most of the time, in April, May, or June, and sometimes extends into the fall. Being viviparous — as all 52 species of North American natricines (water snakes in the genus Nerodia and garter and ribbon snakes in the genus Thamnophis) are — the female gives live birth to 8-62 (Werler & Dixon, 2000, p. 220), but typically 47 (Greene, 1997, p. 136), young in late August , September, or early October. Such high reproductive rates make this serpent one of the more prolific of our North American ophidians.

This species is found throughout much of the Mississippi valley, from southwest Indiana and extreme southeast Iowa, south to the Gulf and northeast Mexico, as far west as central Texas, most of Oklahoma (save only the panhandle), the southeastern half of Kansas, and portions of Missouri and Arkansas.

I hope you won’t mind if I meander a bit to recall the history of the city of Bullard, near where John took these photos.

Bullard, Texas, is named in honor of John and Emma Bullard, who arrived in the area about 1870 and built a store. The Etna post office opened in Bullard’s store in 1881, putting the small community then in existence on the map. In 1883, the Etna post office was closed, and the Hewsville post office was relocated there and named the Bullard post office. In 1890 the town boasted 200 residents and was home to a number of businesses, a doctor, and a telegraph office.

By 1914 the population doubled to 400. In the 1920s a theater opened up, and a community band was formed. About this time Bullard became notorious for its community holding tank for night soil (a polite euphemism for sewage) that, when full, was hauled twelve miles north to Tyler where it was emptied. There has to be more to that anecdote…

Perhaps the most intriguing bit of history regarding Bullard involves the nearby but now long-gone community of Burning Bush. In 1913 a sect of free Methodists, angered by the increasing formality of Methodism, established a colony here intending to live out their convictions that Biblical mores (as they understood them) must be adhered to. In many ways they mirrored the 1620 colony established in the Americas under the Mayflower Compact. All property was owned by the community, none by individuals. All land was farmed by the group, and all shared in the bounty. Except, as with all those who had come before (and, I hasten to add, those who came afterward as well), there soon was no bounty to be had. By 1919 (the year my mother was born) the debts of the community reached the breaking point and all assets of Burning Bush were auctioned on the courthouse steps… Another sad — but highly instructive — example of how human nature and socialism simply don’t gel.


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 jerry.cates@entomobiotics.com. You may also leave a comment in the space provided below.


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