# Non-morphing tads???



## Ed Martin (Mar 25, 2004)

I was not sure how to title this thread, but I have a tinc tadpole that has been in the water for eleven months and has no legs at all. I raised it communally with it’s clutch mates and all of them morphed normally. I have moved it and added it to other tadpole enclosures and while all the others morphed he stayed the same. Other than the fact that it is not morphing, the tad seems healthy. I was actually thinking about putting him in a bowl on my desk or something because I’m now resigned to the idea that he will not morph. Has anyone else seen this? Any theories as to why it would happen. 
Ed


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## booboo (Jan 22, 2005)

I know tikifrog had an azureus tad that was 14 months old but no fronts and eventually died. I am pretty sure it is a from of sls.


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## Grassypeak (Jun 14, 2005)

Maybe it is a form of neoteny (spelling?). There is mention of this in another thread which I cannot find. Someone called them methulisa tadpoles and someone mentioned having an azures for three years before it died. As I remember it the azures tadpole developed a very nice broad finned tail!


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## elmoisfive (Dec 31, 2004)

Ed,

I have a leuc tad that has been in the water for the better part of 6 months now. It developed a couple of tiny appendages (little nubs) where the back legs should be and then development stopped. Seems very healthy otherwise. No other leuc tad has shown this issue so it's odd. He seemed to have a rough start after hatching though I don't know if that was cause or effect. 

I've become quite attached to the little bugger and will keep him alive for as long as he can make it. He's kind of cute in a way though it is sad knowing that he won't ever develop.

Bill


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## Afemoralis (Mar 17, 2005)

*Neoteny*

Hey Grassypeak,

Neoteny (or paedomorphosis really) would be really cool to find in a frog- and it would be a first. It's common in salamanders, but reproductive tadpoles are another beast all together. It would be a knock-your-socks-off world wide shocker. Most amphibian biologists don't think it would be physically possible due to the physical restructuring that would be nessesary. 

The other end of the spectrum, peramorphosis (the speeding up of development), or at least peramorphic traits, have been documented in tadpoles though. Budgets' frog, Lepidobatrachus, have full on carnivorous frog jaws to eat other tadpoles with. 

It's worth checking out. The whole spectrum that includes paedomorphosis and peramorphosis falls under the biological term "heterochrony."

Cheers!

Afemoralis


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## Guest (Jan 30, 2006)

I saw this in the vittatus


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## Dane (Aug 19, 2004)

Do a search on Methuselah tads. Interesting topic.


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## KeroKero (Jun 13, 2004)

Its not a form of SLS when the back legs don't even develop. I've heard of this happening in a number of different PDFs, never morphed, eventually died. I wouldn't say this is any form of neoteny as there is no way these frogs are going to reproduce, and is more of a glitch in the system of some kind (salamanders from what I understand don't go thru as extreme a change and that's probibly why the neoteny is possible in them). Either a glitch in the frog development, or environmental glitch that has kept the tad from having the correct hormonal changes needed for metamorphosis to complete.


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## Ed (Sep 19, 2004)

snip "Its not a form of SLS when the back legs don't even develop. I've heard of this happening in a number of different PDFs, never morphed"

If you dig back into the literature SLS also does occur with the front and hind legs failing to develop but this was early in the attempts to resolve the syndrome. I suspect that this is not seen anymore due to some the of the nutrional advances. 

It wouldn't be SLS anyway as the tadpole has not proceeded in development (tail absorbtion, body morphology etc) and is probably due to a disruption in the endocrine system (developmental defect, mutation, tumor). It is not paedeomorphic as the tadpole cannot sexually mature (as the sexual organs are still mere spots of cells in the tadpole stage). 

Non-developing tadpoles have also been reported several times in the frognet archives. 

Ed


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## dmartin72 (Oct 27, 2004)

What do you do with them?


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## Afemoralis (Mar 17, 2005)

*Hmmm....*

Has anyone tried adding iodine? You can tweak the metamorphic rates of other frogs this way...

Just an idea.

Afemoralis


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## Guest (Jan 31, 2006)

i have seen vittatus with something called "spindly leg syndrome" i know that i seen that in a book about PDF's and Mantellas but now i don't know where...


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## Ed (Sep 19, 2004)

As a comment I would not suggest trying to get them to metamorph as if it has a genetic component and the tadpoles were morphed, then we would be spreading deleterious genes into the population. As for what to do with the tadpole, set it up and see how big it will get (as the should grow throughout thier entire life) or euthanize it. 

If the water is dericient in iodine, then the addition of iodine will stmulate an increased level of thyroxine which can stimulate metamorphosis however it is also possible that the issue is not with production of the hormones triggering metamorphosis but in the receptors. It is possible that the tadpole lacks sufficient receptors for the hormone, is producing an aberrant hormone, or even has some other disruption. 

Spindly-leg syndrome is known as SLS, there has been a lot of discussion on the boards here and in the frognet archives. 
In short "classic" SLS occurs when the front legs of the froglet do not develop or develop abnormally. The froglet can have no front legs, one front legs, two front legs that are not usuable, or even two front legs that are visibly thin but usable. In all but the last case the froglet usually dies from starvation. There are multiple "cures" implying multiple causes hence the use of the phrase syndrome. 

Ed


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## jschroeder (Mar 19, 2005)

I was thinking about iodine as well. I used it once on a Copes Giant salamander I found to see if I could get him to morph, and it worked. The only difference between the Copes and Pacific Giant salamanders is that the Copes never leaves the water.

It was an interesting experiment, no idea if it would work in this instace though.


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## elmoisfive (Dec 31, 2004)

Here is a recent photo of my non-morphing Leuc 'forever tad' who has been in the water for 6 months now. Note the very small hind leg stumps that sprouted at roughly 6 weeks give or take a few days and then stopped growing. The pigmentation is also all messed up compared to normal leuc tads as well. He seems healthy enough but obviously is never going to make it.

Bill


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## Dane (Aug 19, 2004)

I believe I've read that they can even develop adult coloration over time, and get really large ornately finned tails. Cool looking tad btw.


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## RussS (Oct 11, 2005)

elmoisfive said:


> Here is a recent photo of my non-morphing Leuc 'forever tad' who has been in the water for 6 months now. Note the very small hind leg stumps that sprouted at roughly 6 weeks give or take a few days and then stopped growing. The pigmentation is also all messed up compared to normal leuc tads as well. He seems healthy enough but obviously is never going to make it.
> 
> Bill
> 
> ...


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## elmoisfive (Dec 31, 2004)

Russ,

He's ~ 1.75 inches long so a good size fellow. Essentially the same size as our other leuc tads that go onto morph into froglets.

Bill


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