Ambystoma maculatum variation

[Palex134]

I have noticed a difference in the spotting coloration between A. maculatum localities. After seeing some collected maculatum from the South Eastern USA, I noticed the first couple of spots were a darker yellow, orange, or almost red. All the maculatum I find in Maine do not have any variation, just a uniformal yellow for each spot. Can anyone elaborate on this more, has it been proven that different localities have the different spot colorations? Sorry, I am new to amphibians.

Also, I found a very aberrantly patterened juvi A. maculatum a few years back in one of my herping spots in Maine, and recently showed a picture to a Biology/Herpetology Professor at a University. The Professor was quite amazed at the lack of uniform spotting. I hadnt thought much of it until then. The juvi had very few circular spots, but had lots of zig-zag patterning. How normal is this? Do you suggest I go back to the area and look around for more with a similar pattern?

Thanks!

 

[Otterwoman]

Here are some from the area around Kingston, NY. They are all from the same egg clutch, and I think they show a lot of variation just among themselves.

 

[Slimy2]

I don't have a good picture of my spotted but its spots get oranger and oranger towords the tip of the head.

 

[Palex134]

I don't have a good picture of my spotted but its spots get oranger and oranger towords the tip of the head.

Yes, that is what I am refering to. All the ones I find in the North East USA have the same yellow all throughout their body, while others I have seen get more orange. Is this due to their locality?

 

[Slimy2]

hmm...

I always thought that as they get older and larger that their spots became more orange.

 

[dane_zu]

I think its just genetics, alot have them and a lot dont(the orange spots that is)

I dont think it has to deal with only a specific area in their range, that being said, here is a couple from northern Wisconsin
this is one i found this summer, it was huge and sported orange spots on its head

and here are pics of other ones I found in the same area

this is a juvie

 

[will_j]

I have a theory. Just a theory mind! If you look at Salamandra salamandra subspecies and variations. generally the further south you go, the greater the variation in pattern. could it be that the southern populations were relatively unaffected by ice advances during the ice age and so have had longer for genetic mutations to occur, whereas Maine, which was almost certainly covered by ice sheets lost any original populations, and those that recolonised have not had long enough to develop variation to the degree of the southern animals.

I now expect you to pick at the holes in this

 

[woodsman]

Variations in A. maculatum

Just a small hole I'd like to poke in the theory of less variation farther North. I'm not a herp specialist, but in native plant species, the non-continuous nature of the Wisconsin Ice Sheet created many small isolated populations. These populations were, therefore, closed to any breeding with other groups and many were on their way to new species-hood. When the glaciers retreated and the expanding pocket populations were reconnected by range expansion, all of the new isolated "island" populations resulted in a greater amount of variation along the Northern range limits than in the "major" population centers further South.

This hypothesis works very well with many plant species, but I am completely (!) ignorant when it comes to A. maculatum. Here on Staten island, though, we have both Northern and Southern populations of Ring-neck Snakes, with all "shades" of hybrids in between. So, at least in this herp, I feel the hypothesis still holds.

I'd love to see the Maine "Spotties" sometime!. Richard Lynch in Staten Island, NYC.

 

[Nathan050793]

I just thought I'd add that the entire 5 years I lived in Maine, I never found any A.maculatum with orange spots. I found them often and even raised a few from larvae, but still no orange.

 

[cecalak]

Also, I can't remember the exact citation right now, but there is some evidence that spot patterns can be related to stress levels experienced by the organism at the time of metamorphosis. The authors noted that patterns were more asymmetrical when organisms had higher levels of stress hormones.

 

[kingswede]

orange spots

The presence or absence of orange spotting on the dorsum varies among local and regional populations. Years back i found a large adult in upstate NY with 2 very intense orange spots on it's head but from 2 metamorphs in north carolina ( both from the same vernal pool) i found that only one had the orange spots on it's head.

 

[will_j]

Just a small hole I'd like to poke in the theory of less variation farther North. I'm not a herp specialist, but in native plant species, the non-continuous nature of the Wisconsin Ice Sheet created many small isolated populations. These populations were, therefore, closed to any breeding with other groups and many were on their way to new species-hood. When the glaciers retreated and the expanding pocket populations were reconnected by range expansion, all of the new isolated "island" populations resulted in a greater amount of variation along the Northern range limits than in the "major" population centers further South.

This hypothesis works very well with many plant species, but I am completely (!) ignorant when it comes to A. maculatum. Here on Staten island, though, we have both Northern and Southern populations of Ring-neck Snakes, with all "shades" of hybrids in between. So, at least in this herp, I feel the hypothesis still holds.

I'd love to see the Maine "Spotties" sometime!. Richard Lynch in Staten Island, NYC.

interesting information! you may well be right about the herps

 

[amkid247]

well this is my guy, i've never seen any with orange up in <location removed by John> where i encounter them, but then again i only see juveniles. he's a juvenile from this year, metamorphosed in august.