Reptile & Amphibian Forums

Hello everyone. I've been on the bearded dragon & gecko forum quite a bit for the last couple months and I just opened the morph discussion tonight and read a few posts. I see there are some very knowledgable people here and had a question I hope some people can answer. I'm not sure if anybody follows bearded dragons, but I have a new morph I have been working on for about 2 years now. These animals are missing or have a reduction in the iridiphores (white). I tried to do some research on the internet and even contacted some universities to find out if there were any records of reptiles missing or having a reduction in the iridiphores. So far I have found none. Is there anyone out there that knows of any reptile missing the iridiphores? Any information would be greatly appreciated.

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Paul Morlock
of CaptiveCreations and
Retail Sales Rep. for Sandfire Dragon Ranch

Well... if there's a solid yellow GTP out there somewhere... it would be missing the iridophores.... they're responsible for the Tyndall scattering that produces blue, right? Other than that, I've never heard of one. Snake breeders probably wouldn't even recognize it for what it was.
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Peter: It's OK, I'll handle it. I read a book about something like this.
Brian: Are you sure it was a book? Are you sure it wasn't NOTHING?

interesting... I'm not 100% sure, but I do not think that tyndall blue and the iridiphores are the same thing, though they may produce similar effects. If a GTP was missing the iridiphores then this would definately effect the belly scales also since they generally contain large ammounts of iridiphores. I believe that tyndall produces a "blue color" while the iridiphores just reflect/refract light and produce a "blue iridescence".
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Paul Morlock
of CaptiveCreations and
Retail Sales Rep. for Sandfire Dragon Ranch

FWIW, over the past 20 years a number of smooth green snakes have turned up in my back yard. Five of them were a fairly light brown instead of green. Yellow pigment leaked out of the skin leaving a coal black snake when I pickled one in formalin. So I think the lack has something to do with the iridophores.

I haven't tried to breed these brown-colored green snakes, so I can't prove the condition is genetic. But the repeats indicate that it very likely is.

While I've never seen one, I've heard that yellow bullfrogs have turned up.

Have you looked through the pictures in Bern Bechtel's Color Variations in Amphibians and Reptiles?

Paul Hollander

No, I haven't seen that book. I will have to check it out. I don't think the abscence of iridiphores are responsible for the brown green snakes. The iridiphores don't actually produce color themselves. The yellow, orange & red pigments in reptiles are produced by the xanthophores. The iridiphores are responsible mostly for whites and/or irridesence. I'm not sure how the yellow bled out when the snake was pickled, but it's hard to believe that it actually had anything to do with the mutation. I believe it was most likely due to the chemical. Cells that produce pigment in the skin are usually located in the lower layers where they are protected and not in the upper layers where they can be shed or damaged. You mentioned yellow bullfrogs....are you referring to the albinos? The albinos are yellow because they are missing the melanin. Thanks for the input though. Keep 'em coming.

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Paul Morlock
of CaptiveCreations and
Retail Sales Rep. for Sandfire Dragon Ranch

>I don't think the abscence of iridiphores are responsible for the brown green snakes. The iridiphores don't actually produce color themselves. The yellow, orange & red pigments in reptiles are produced by the xanthophores. The iridiphores are responsible mostly for whites and/or irridesence. I'm not sure how the yellow bled out when the snake was pickled, but it's hard to believe that it actually had anything to do with the mutation. I believe it was most likely due to the chemical.

All of my brown green snakes have been brown when captured. All but one of them were released alive within an hour of capture. One of these snakes died after two months in captivity. The color did not change until I preserved it.

Iridophores contain guanine crystals that are responsible for blue as well as white coloration through refraction of light. Green is produced by a combination of blue and yellow. Yellow/red pigment is soluable in formalin. My snake had yellow pigment, as proved by the pigment going into solution and turning the formalin yellow. After the yellow pigment dissolved, the preserved snake was black, so the snake had both melanin and yellow pigment when alive.

As melanin and yellow pigment were present in the snake, what caused the snake to be brown instead of green? My hypothesis is that my snake was brown because the snake could not produce blue the way a normal green snake would. IOW, either the iridophores were absent, or they didn't contain normal guanine crystals. Alternative hypotheses?

Paul Hollander

ok... that makes sense. I did not realize that xanthophores were soluble in formalin. I then would agree with you. Thanks!Do you have any pics?
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Paul Morlock
of CaptiveCreations and
Retail Sales Rep. for Sandfire Dragon Ranch

Mine are doing great!! Thanx.....

Hey Mike. What's up? Happy New Year. That pic is one of Bob's frogs taken at the ranch. Took forever to catch the damn thing. LOL. Mine are doing great. Just moved them in to a new tank. They are loving it! Glad to hear yours are doing good. Will you be at Hamburg next week?
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Paul Morlock
of CaptiveCreations and
Retail Sales Rep. for Sandfire Dragon Ranch