RAUK - Archived Forum - Oddity

This contains the Forum posts up until the end of March, 2011. Posts may be viewed but cannot be edited or replied to - nor can new posts be made. More recent posts can be seen on the new Forum at http://www.herpetofauna.co.uk/forum/

Forum Home

Oddity:

Author Message
Peter
Senior Member
Joined: 17 Jan 2008
No. of posts: 260


View other posts by Peter
Posted: 17 May 2008

Whilst swabbing for Chytridiomicosis recently, we encountered a slight oddity, a male smooth newt that displayed certain features normally attributed to a male palmate newt.

This particular individual was at first glance a normal male smooth newt. On closer examination however, the animal displayed a crest that was the height of a smooth newt`s, but which was straight edged as in the case of a male palmate newt with very little or no trace of undulations.  The animal also had more than the average amount of fringes on its toes which gave the appearance of webbing. Furthermore the animal had a definate filament at the end of it`s tail. We popped the animal into a glass jar and prior to release, my volunteer snapped a few pics with his mobile. The filament is clearly visible at the end of the tail. Anybody that has experience of our indigenous newt species would at first glance identify the animal as a male smooth newt. Of the 30 plus animals which were encountered at this site, this was the only animal displaying this combination of features. There may well of course be more, as 30 animals is a mere fraction of the colony size.

Both palmate and smooth newts were present in good numbers at the site.

Is there anyone here that is familiar with T.vulgaris morphology or whom has had any similar experience of finding oddities such as this? If so, then I would be very interested to know about it.


Peter39587.3778819444



Jeroen
Senior Member
Joined: 03 Nov 2004
No. of posts: 121


View other posts by Jeroen
Posted: 17 May 2008

Dear Peter,

My guess would be that you found a hybrid. I am aware of only two records (one from the UK and one from France) of a helveticus x vulgaris hybrid, so they seem to be very rare. There is, however, one other possibility. You might be dealing with an introduced specimen of one of the southern subspecies of the smooth newt. Both meridionalis (Italy and adjacent areas) and graecus (Balkans) display a straight-edged crest and a tail filament. Difference between them: graecus has (or at least much clearer) additional dorsolateral crests (or rather ridges) like helveticus (can't really tell from the pictures whether this is the case or not). I have some pictures of both subspecies (besides the nominal form) here => http://nemys.ugent.be/species.asp?spec=44665&group=16&am p;act=4&p=0

Most likely you found a very rare hybrid, but to be really sure, some molecular analyses would be desirable, I guess. 

g's,

J.


Jeroen Speybroeck
http://www.hylawerkgroep.be/jeroen/
Peter
Senior Member
Joined: 17 Jan 2008
No. of posts: 260


View other posts by Peter
Posted: 17 May 2008

Thanks for the very interesting reply.

I`ll try and obtain that sample if there is a next time!

I will be returning to the pond so it`s not beyond the realms of possability.

In the case of recorded hybrids between the two species, do we know if such animals are fertile?

 

EDIT:   The pond owner`s also took a few snaps, and were armed with a much better camera.  I shall attempt to track down the images

Peter39585.3992708333



Jeroen
Senior Member
Joined: 03 Nov 2004
No. of posts: 121


View other posts by Jeroen
Posted: 17 May 2008

[QUOTE=Peter]In the case of recorded hybrids between the two species, do we know if such animals are fertile?[/QUOTE]

By definition, hybrids are infertile. This holds also true for (the few recorded) hybrids of these species. Species that are less distant from an evolutionary perspective do, however, produce partially fertile offspring = reproduction possible, but with clearly reduced fertility. This, of course, being a simplification of matters such as speciation, introgression, hybridogenesis (water frogs), ... .

g's,

J.

 


Jeroen Speybroeck
http://www.hylawerkgroep.be/jeroen/
David Bird
Forum Specialist
Joined: 17 Feb 2003
No. of posts: 515


View other posts by David Bird
Posted: 17 May 2008
There are apparently quite a few of these hybrids now recorded. I had a photo of one sent to me by a forum member the other month and came to the same conclusion as Jeroen but as this was in his garden pond where no Balkan specimens had been introduced the hybrid was much more likely.

David
British Herpetological Society Librarian and member of B.H.S Conservation Committee. Self employed Herpetological Consultant and Field Worker.
Peter
Senior Member
Joined: 17 Jan 2008
No. of posts: 260


View other posts by Peter
Posted: 17 May 2008
[QUOTE=Jeroen]

 Species that are less distant from an evolutionary perspective do, however, produce partially fertile offspring = reproduction possible, but with clearly reduced fertility. This, of course, being a simplification of matters such as speciation, introgression, hybridogenesis (water frogs), ... .

g's,

J.

 

[/QUOTE]

 

As in the case of Felis silvestris and Felis silvestris catus then?





Huddy
Member
Joined: 09 Feb 2006
No. of posts: 18


View other posts by Huddy
Posted: 17 May 2008

Hi Peter ,

               I am the forum  member that Dave mentions in that last post .I too would agree that you too have found a smooth/ palmate hybrid. I sent pics of the animal that I found off to Richard Griffiths at DICE and he too agreed it was a hybrid specimen . Richard is one of the co authors of the "New Naturalist Reptiles and Amphibians" and within the book he refers to a hybrid that he found at a pond in mid Wales ,photo included (black and white) , also John Buckley of the HCT sent me pics last month of a hybrid that he found in his garden pond .

I would not be suprised if there are a lot more of these hybids out there , perhaps folks just Don't idenify them correctly and further to this ,female smooth /palmate hybrids would be extreamly difficult if not impossible to I.D  


Peter
Senior Member
Joined: 17 Jan 2008
No. of posts: 260


View other posts by Peter
Posted: 18 May 2008

Thank you for the response David.  I would agree that it is far more likely that the animal is a hybrid.  The pond is surrounded by a considerable amount of farmland so I would have thought that the likelihood of European introductions in the vacinity would be extremely slight.

Thank you for posting Huddy. No I certainly wouldn`t rate my chances at identifying a female smooth/palmate hybrid either!

 

Do you still have the images of the animal that you speak of available?





Peter
Senior Member
Joined: 17 Jan 2008
No. of posts: 260


View other posts by Peter
Posted: 19 May 2008

The owner of the pond has forwarded me a few more snaps of the likely hybrid.

The tail filament (a helveticus characteristic) is plain to see in the above image.  Below the crest can be seen to be the height we would expect from vulgaris but the straight edge associated with helveticus.

 

 

Above is a view of the speckled throat and below an overall view of the animal.

 

Peter39587.5593518519



Jeroen
Senior Member
Joined: 03 Nov 2004
No. of posts: 121


View other posts by Jeroen
Posted: 20 May 2008

[QUOTE=Peter] The pond is surrounded by a considerable amount of farmland so I would have thought that the likelihood of European introductions in the vacinity would be extremely slight.[/QUOTE]

Hmmm, you'd be surprised to see at what strange spots the weirdest alien invasive species have popped up. Nevertheless, I still agree a hybrid, while not certain, is much more likely to be the case, and it is interesting to learn that they are not as rare as I had been reading so far.

g's,

J.

Jeroen39588.4933101852
Jeroen Speybroeck
http://www.hylawerkgroep.be/jeroen/
Caleb
Forum Coordinator
Joined: 17 Feb 2003
No. of posts: 448


View other posts by Caleb
Posted: 22 May 2008
[QUOTE=Jeroen]

[QUOTE=Peter]In the case of recorded hybrids between the two species, do we know if such animals are fertile?[/QUOTE]


By definition, hybrids are infertile. This holds also true for (the few recorded) hybrids of these species. Species that are less distant from an evolutionary perspective do, however, produce partially fertile offspring = reproduction possible, but with clearly reduced fertility. This, of course, being a simplification of matters such as speciation, introgression, hybridogenesis (water frogs), ... .


[/QUOTE]

T. vulgaris x T. helveticus hybrids have been recorded successfully breeding with the parent species (at reduced fertility), according to:

Macgregor, H. C., Sessions, S. K., & Arntzen, J. W., 1990. An integrative analysis of phylogenetic relationships among newts of the genus Triturus (family Salamandridae), using comparative biochemistry, cytogenetics and reproductive interactions. J. Evol. Biol. 3: 329-373.

(They state that T. vulgaris x T. montandoni hybrids can also breed with the parent species; the cristatus group is also well known to produce viable hybrids. )
Peter
Senior Member
Joined: 17 Jan 2008
No. of posts: 260


View other posts by Peter
Posted: 22 May 2008
Caleb, I tried to find the paper that you mentioned.  I can only find references to it.  Is it available in full anywhere that you know of?



Caleb
Forum Coordinator
Joined: 17 Feb 2003
No. of posts: 448


View other posts by Caleb
Posted: 22 May 2008
You should be able to get a pdf here.

(Or if that doesn't work for you, you should be able to get it via the contents page here.)

It's a big one (and some of it's a bit out of date), but it's well worth reading. The hybridisation stuff is on page 339.
Peter
Senior Member
Joined: 17 Jan 2008
No. of posts: 260


View other posts by Peter
Posted: 22 May 2008

[QUOTE=Caleb]You should be able to get a pdf here. [/QUOTE]

 

Got it, thanks.





Jeroen
Senior Member
Joined: 03 Nov 2004
No. of posts: 121


View other posts by Jeroen
Posted: 23 May 2008
[QUOTE=Caleb]
T. vulgaris x T. helveticus hybrids have been recorded successfully breeding with the parent species (at reduced fertility)[/QUOTE]

Thanks a lot, Caleb, for correcting my mistake - interesting. Apologies to Peter.

Jeroen39591.1483333333
Jeroen Speybroeck
http://www.hylawerkgroep.be/jeroen/
Peter
Senior Member
Joined: 17 Jan 2008
No. of posts: 260


View other posts by Peter
Posted: 23 May 2008

No apologies needed Jeroen!

It`s all very interesting stuff.





- Oddity

Content here