Has anyone studied Northern x Southern ringneck hybrids?

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incuhead2000
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Has anyone studied Northern x Southern ringneck hybrids?

Post by incuhead2000 » February 15th, 2015, 5:27 pm

Hey All,

So if all ringnecks except the Northern ringnecks are known for being venomous and having rear fangs has anyone done studies on the intergrades too see if the maxillary fangs and duvernoys gland are present in the cross? I am really curious and if anyone has any information could you please send it my way I would really appreciate it!
Thanks!
Michael Kirby

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AndyA1031
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Re: Has anyone studied Northern x Southern ringneck hybrids?

Post by AndyA1031 » February 16th, 2015, 10:49 am

Interesting. I come across quite a few intergrades in the northern MD counties, but never thought to look. No studies as far as I know. As I find them this year I might be able to check a few, or at least ask around!

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spinifer
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Re: Has anyone studied Northern x Southern ringneck hybrids?

Post by spinifer » February 17th, 2015, 5:51 pm

I'm curious where you heard that the condition is not present in Northerns.

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Re: Has anyone studied Northern x Southern ringneck hybrids?

Post by FrogO_Oeyes » February 19th, 2015, 7:42 am

Absence of fangs is one of the diagnostic and definitive traits of Diadophis edwardsii. You'll find it commonly mentioned in field guides.

When Diadophis phylogeography was studied, I don't recall any evidence of hybridization of D.edwardsii being presented, although that's definitely a possibility in a few areas along the Appalachians. Additional studies showed that D.arnyi and D.stictogenys do not have a broad intergrade area, but rather have slightly different ranges and fewer reliable diagnostic traits [ie, they can look much alike, but scale counts reliably distinguish them, with most "intergrades" being D.stictogenys].

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incuhead2000
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Re: Has anyone studied Northern x Southern ringneck hybrids?

Post by incuhead2000 » February 19th, 2015, 10:46 am

AndyA1031 wrote:Interesting. I come across quite a few intergrades in the northern MD counties, but never thought to look. No studies as far as I know. As I find them this year I might be able to check a few, or at least ask around!
Cool, let me know what you come up with!
spinifer wrote:I'm curious where you heard that the condition is not present in Northerns.
Almost every book out there fails to mention that they are venomous, I can't find any book that says they have maxillary fangs. Is there evidence to support that they do? I am very interested in this so if there is any information in the form of scientific papers please let me know, I can't find much out there since it seems ringnecks are understudied. Otherwise I will start checking all my DORS if they are in good enough shape to check for the presence of maxillary fangs.
FrogO_Oeyes wrote:Absence of fangs is one of the diagnostic and definitive traits of Diadophis edwardsii. You'll find it commonly mentioned in field guides.

When Diadophis phylogeography was studied, I don't recall any evidence of hybridization of D.edwardsii being presented, although that's definitely a possibility in a few areas along the Appalachians. Additional studies showed that D.arnyi and D.stictogenys do not have a broad intergrade area, but rather have slightly different ranges and fewer reliable diagnostic traits [ie, they can look much alike, but scale counts reliably distinguish them, with most "intergrades" being D.stictogenys].
A lot of ringneck intergrades seem to show up in areas of overlap on the East coast but other than observations of belly dots and split neck ring without DNA evidence it is hard to prove which is which.

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Re: Has anyone studied Northern x Southern ringneck hybrids?

Post by FrogO_Oeyes » February 19th, 2015, 11:09 am

Experimental evidence that oral secretions of northwestern ring-necked snakes (Diadophis punctatus occidentalis) are toxic to their prey
http://masonlab.science.oregonstate.edu ... gnecks.pdf
Ring-necked snakes (Diadophis punctatus) do not possess a true venom gland, but do have a Duvernoy’s gland, which is derived from the same tissue (Taub, 1967; Mackessy, 2002). Most subspecies of D. punctatus, with the apparent exception of the fangless D. p. edwardsii, are rear-fanged with the last maxillary teeth larger than the preceding ones and separated from them by a space (Fig. 1; Blanchard, 1942).
I haven't located an original source on the fanglessness of D.edwardsii. It could be Blanchard's 1942 monograph, or Merrem's 1820 description. I did find a [Virginia, 1960] herp society mention of a northern/southern hybrid, but didn't actually find the text within the pdf available online. As noted though, without genetic confirmation, there's no certainty of it being a hybrid.

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Re: Has anyone studied Northern x Southern ringneck hybrids?

Post by incuhead2000 » February 19th, 2015, 5:09 pm

I took the time to read that paper, thank you for sharing it I found it very interesting! :thumb:

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Re: Has anyone studied Northern x Southern ringneck hybrids?

Post by NewYorkHerper16 » February 20th, 2015, 11:41 am

Very interesting. I actually had a small reaction to an edwardsii bite once. It was a very large and aggressive individual that got me right on the soft piece of skin between my fingers. I let it chew for a while because i thought it was funny that ringneck could be so aggressive, and there was a very slight tingling sensation after the bite. It was a little red too.
I've never considered that the northerns would have any different traits then any other subspecies (other than some phenotypical traits like color or pattern), but do we know for sure whether or not edwardsii possess the Duvernoy's gland like other subspecies? Maybe they do, but it might be possible that they just lack an effective means of delivering that venom, like maxillary fangs It is also possible that certain populations in different regions have different "venoms" if you could even call it that, based on prey choices. I feel like i remember reading somewhere that ringnecks' diets can be very specific in certain areas, which could influence whether or not they possess some type of venom to subdue their prey.

All of what i just said is just speculation and personal experience, so i may be completely wrong with what i said here. This is such an interesting topic though!

-Alex

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incuhead2000
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Re: Has anyone studied Northern x Southern ringneck hybrids?

Post by incuhead2000 » February 22nd, 2015, 6:14 pm

Yes it is believed that ringneck venom is prey specific and toxicity varies among the subspecies. I just wish there was more literature on it because I enjoy learning new things and for some reason this topic sparked my interest so I felt the need to start fishing for information.

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