Reptile & Amphibian Forums

I just wanted to share a few pictures of Gulf Salt Marsh Watersnakes (Nerodia clarkii clarkii) that I've enountered over the past three months in the panhandle of Florida.

A habitat shot: Spartina grass, Needlerush, and a Palm hammock.

The first was collected in July in Taylor County, FL.

The lateral spotting on her posterior half indicates ancestral hybridization with Nerodia fasciata. She was collected in a brackish creek near an impoundment where human disturbance has blurred the interface between salt marsh and fresh water habitats.

I encountered the following individuals in intact salt marsh in Wakulla County, FL. The phenotypic difference is obvious.

An adult male found foraging in a tidal creek at a dusk low tide.

Their venters are spectacular.

Another adult male caught approximately 45 minutes later.

The hybrid female from above gave birth to 5 babies on 8-19-04.

Mother and child.

Giving birth.

Neonate in amniotic sack.

Female giving birth and a curious neonate.

Three neonates.

Neonate.

Neonate.

Neonate showing a strong fasciata phenotype.

Neonate.

Neonate.

These hybrid snakes typically only come from coastal areas that have experienced anthropogenic disturbance. Unfortunately, this has challenged the genetic integrity of Nerodia clarkii clarkii over large portions of its range. Sadly, the species may be hybridized out of existence if coastal development isn't abated. It's a very interesting issue and one I hope to investiagte mush further in the future.

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Pierson Hill

Herpetology and Herpetoculture

Very interesting and great pics! I still wish my collection hadn't caught a nasty bug last year. I lost a great looking hybrid confluens x clarkii. There are a ton of hybrids in this one particular area, yet I havn't seen any in other areas where I have found both clarkii and Nerodia.
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Andy Maddox
AIM: thekingofproduct
MSN: Poloboy32486@hotmail.com
Yahoo:surfandskimtx04
Houston Herp Key
The Reptizone

"A yellow ribbon instead of a swastika. Nothin' proper about ya propaganda. Fools follow rules when the set commands ya. Said it was blue when ya blood was red. That's how ya got a bullet blasted through ya head"- Rage Against the Machine

Is the area where you see the hyrbirds diked off or is there some sort of human manipulation of the brackish-fresh water interface? Also, are there roadways with adjacent deep ditches through the salt marsh? Is it routinely flooded during storms? I'm trying to put together a conceptual picture of what conditions promote hybridization and any info would very helpful.
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Pierson Hill

Herpetology and Herpetoculture

It floods a fair deal. The spot is on eastern Galveston Bay, not far from Bolivar. I am not sure on the human effects as it is actually in/near a wildlife refuge that we have found these snakes. I don't think there is much out there that people have done to modify it, but there could be some stuff such as dredging going on nearby that I don't know of. You might remember seeing some of the pics on the other forum last year that bowers posted. I don't think any of us has seen a pure clarkii out there though. I could be wrong, but I can't recall hearing that BB or scott found one and I know I havn't found a pure one. If you would like, you can probably shoot BB an email and ask him so more questions as I have only herped the area occasionally.
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Andy Maddox
AIM: thekingofproduct
MSN: Poloboy32486@hotmail.com
Yahoo:surfandskimtx04
Houston Herp Key
The Reptizone

"A yellow ribbon instead of a swastika. Nothin' proper about ya propaganda. Fools follow rules when the set commands ya. Said it was blue when ya blood was red. That's how ya got a bullet blasted through ya head"- Rage Against the Machine

It is a shame that hybridization may pretty much wipe the pure ones out. I am all for hybridixzing in captivity (to a cetain point and not hybridizing for the heck of but for a better looking animal) but I hate it in the wild. I have done little heping and far between this summer because there is sooo much to do here that needs gettin done so I ahev not found any realy special snakes this year. Maybe next year I'll do better.
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Justin

What? How can you be agaisnt hybridizing and intergradation in the wild? If it happens in the wild, then it is usually a pretty natural thing. Clarkii and fasciata share many characteristics, at least physically, and clarkii was once in the genus fasciata. If anything, I would be against hybrids in captivity. That is where you can get problems. People are sold animals that are hybrids unwittingly, and then breed them and sell more hybrids without even realizing it. If it happens in the wild, then it is something natural. If the species have lasted as long as they have, I doubt some intergradation/hybridization is going to wipe out the species. Do some reasearch on the pond frog, lake frog, and edible frog. Pond and lake frogs breed often and even produce a new species, the edible frog. So if it is natural, I have no problem with it. It is all those people playing god and breeding corns with bullsnakes and what not that I have the problem with.
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Andy Maddox
AIM: thekingofproduct
MSN: Poloboy32486@hotmail.com
Yahoo:surfandskimtx04
Houston Herp Key
The Reptizone

"A yellow ribbon instead of a swastika. Nothin' proper about ya propaganda. Fools follow rules when the set commands ya. Said it was blue when ya blood was red. That's how ya got a bullet blasted through ya head"- Rage Against the Machine

I was talking about I was against it in the wild with the intervention of people and that only. All the other I do aggre with that you said. But when I am for it with captivity I mean like certain species that make a better looking animal. Example of what I mean is like burmese X reticulatd python. The hybrid of that is pretty much hard to make and makes an excellent looking animal. I am for that kind. example of what I am against is somehting like a corn X any sort of king snake or a gopher or something like that. Pretty much I am for hybridizing pythons (some not all) and am against most other hybridized animals. Sorry I did not make it clear to what I meant. I was trying to make a short post. If it is 2 naturally accurring species in the same area for example here there are yellow belly waters and there are midlands. Those are the most common and there are plenty of hybrids between the two and that is alright in my opinion. Do you know what I mean? It is hard to explain what I feel about hybrids. I cannot put it into good words.
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Justin

I have mixed feelings on the hybrid issue. I don't feel that it is wrong in any universal sense but I think people are irresponsible about it. Unknow hybrids on the market is a scary thought, especially with imperiled species like Pituopis ruthveni and Eastern Indigos.

Natural hybrids are probably more common than we think and they are useful indicators of two species' relationship to another. But, I don't like seeing hybridization occur as a result of human activities. Clarkii and fasciata have probably been in delicate balance with one another for thousands of years. Hybridization probably occurred only occassionally during coastal flooding associated with hurricanes. The resulting hybrid genes were either reabsored by the parent populations or eliminated through natural selection. Maybe the spotted animals are easier to see in cord grass and get eaten or maybe they have reduced salt tolerances.

In any case, it's fun to think about.
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Pierson Hill

Herpetology and Herpetoculture

Very cool, Pierson. Are you basing your thoughts here on looks alone? I realize that range overlaps and human intervention are at work , but you certainly must have more to go on than the outward appearance of the snakes, right?
Am I to assume (remember I am very naive when it comes to stuff like this) that an animal will continue to LOOK exactly the same throughout it's entire stay here on planet earth given no influence from other animals? How would we know?
I am sure you are correct in all this, just that I need some clarification.
How the heck do I know what I am looking at? Assumptions must be made I guess.
Are these guys as calm as the mangroves I run into?
Perhaps fasciata IS the species for all of 'em? (as before)
Keep your feet wet!
:Mark

In my experience, in some areas all the clarkii look the same. In these areas, I usually do not see other species of Nerodia around. On ocassion I will find both in an area and the clarkii still appear pure(usually areas closer the beach than the bayous/rivers). But then there is another area where it is brackish and the species are almost a blur. A giant Nerodia melting pot. We found some snakes that appeared as 3 way hybrids. As for the actual snake in the post being a hybrid, there is no explanation for a clarkii giving birth to a snake that looks so much like fasciata other than hybridization. A pure clarkii just doesn't look like that. If you actually see the snakes in person, it is (or at least it has been for me) VERY easy to tell that the clarkii have some definite outside influence.
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Andy Maddox
AIM: thekingofproduct
MSN: Poloboy32486@hotmail.com
Yahoo:surfandskimtx04
Houston Herp Key
The Reptizone

"A yellow ribbon instead of a swastika. Nothin' proper about ya propaganda. Fools follow rules when the set commands ya. Said it was blue when ya blood was red. That's how ya got a bullet blasted through ya head"- Rage Against the Machine

Your observations follow mirror mine Andy. I'd be very interested in herping the area you're speaking of.

Three-way hybrids is a bit surprsing though. Do you know what the third species is?
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Pierson Hill

Herpetology and Herpetoculture

If you ever come up towards Houston we can head out there. My baby that I found was the first one I had seen but then I saw few more DOR's that Scott and BB found and this one crazy broad banded that looked like it had everything imaginable in it.
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Andy Maddox
AIM: thekingofproduct
MSN: Poloboy32486@hotmail.com
Yahoo:surfandskimtx04
Houston Herp Key
The Reptizone

"A yellow ribbon instead of a swastika. Nothin' proper about ya propaganda. Fools follow rules when the set commands ya. Said it was blue when ya blood was red. That's how ya got a bullet blasted through ya head"- Rage Against the Machine

Very cool, Pierson. Are you basing your thoughts here on looks alone?

Yes, I am basing my thoughts primarily on looks (which can be a good indicator!) but also on habitat and behavior. Everything is relatively hypothetical at this point but that's how science starts, right?

Am I to assume (remember I am very naive when it comes to stuff like this) that an animal will continue to LOOK exactly the same throughout it's entire stay here on planet earth given no influence from other animals?

Not at all. Environmental conditions can change the way a snakes looks as well. For example, snakes in higher altitudes tend to be darker than their lowland conspecifics (Black Rats, Timber Rattlesnakes, Kingsnakes) so that they can thermoregulate more efficiently. Disturbances such as hurricanes, floods, fires, etc. can cause a bottlenecking effect to genetic drift by killing off the majority of a population and leaving behind a minority group that is genetically unrepresentative of the parent population (goini?). Sexual selection can cause an animal to change, even to the point where the changes hamper its survival (classic example = peacocks). Animals change all the time in response to a thousand different factors. It's the form that can adjust to all these factors simultanesouly that is the the longest lasting.

We know this because we can recreate population dynamics in an experimental setting and control for different factors. Haven't you ever toyed around with feeder mice colonies Mark? I started out with 80% amelanistic mice and by preferentially feeding off amel babies, I almost eliminated the amel gene from my mice colony within a year.

Perhaps fasciata IS the species for all of 'em? (as before)

The more I learn, the more I realize that animals don't behave in accordance with our species concepts. The spcies concept works most of the time fairly well but their are too many exceptions to ignore. I will say that axonomy is a great tool for scientific communication, but it is an imprecise tool.

Let me see if I can illustrate my point a little better:

I only find entirely striped snakes in coastal areas that have not been developed. The interface between spartina salt marsh and mainland habitats is usually intact save for an occassional small roadway an associated ditches.

Once I venture into areas that are diked or drained, have beach houses, or have some other sort of immediate habitat alteration I start finding the spotted forms. The intensity of the spotting/banding and frequency of spotted individuals has been proportional to the disturbance of habitat. I find these spotted individuals outside of salt marsh too. For example, that female I posted was found in a shallow freshwater ditch lined with sawgrass. The creek eventually flowed into salt marsh but not for several hundred meters from where she was found. I have found pure fasciata in the immediate area.

I realize that range overlaps and human intervention are at work , but you certainly must have more to go on than the outward appearance of the snakes, right?

This isn't supported by many specimens but I have noticed a tendency for the spotted forms to be larger, have thicker heads, and be much more prone to bite when captured. Hell...even my spotted CB animals are more bitey than their striped siblings. This could be due to fasciata genetic influence or could be the same phenomenon scene in some Thamnophis species: striped babies are more prone to flee and checkered babies are more defensive.

I'd love to do genetic work in the future, especially on clarkii outside of Florida where little work has been done. I am in touch with a herpetologist who is doing DNA analysis of fasciata/compressicauda/taeniata on the east coast of Florida and he'll be getting DNA from all my animals to include in his analysis. Hopefully he can discern some pattern between a snake's phenotype and their genotpye.

I have to get trained in genetics first though. I couldn't even get into a genetics class here at Davidson this year despite a weeks worth of begging and pleading. It was very frustrating but probably for the best. I've got two Ratsnake spatial ecology papers to write before November so I've got plenty on my plate.

It looks like my feet are going to be wet for a while!

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Pierson Hill

Herpetology and Herpetoculture