Crazy Bombina

[Jeroen Speybroeck]

I am no expert, but when I dug in to this, it seemed like there are (too) many terms and definitions for colour aberrations - imho, it's a bit of a mess. The way I read it, albinism is not seldom, if not most of the time, defined as the same thing as what Michael refers to here as amelanism (e.g. good ol' wiki). A related term is also leucism.

Also, some have a genetic basis (recessive allele expression etc. causing lack of a protein called tyrosinase for albinism), while others may be caused by phenotypic stuff, disease, ... In practical use, a lot of them are used also when not implying 100% lack of melanines, while the genetic basis is usually more "black-and-white"

[Jeroen Speybroeck]

Yes, I think your definitions stick. It's just that everybody start shouting albinism soon, so it seems to fit more than it should. On the other hand, that would mean that I think there has never ever been a record of a true albino fire salamander?
Cf. http://img141.imageshack.us/img141/4162/salamanderd.jpg

[Sandra Panienka]

But to give you an even harder time: All green and blue reptiles for sure, most others as well and I also assume amphibians also have chromatophores.
But this I can explain next time.

What do you mean by "also have chromatophores"? Amphiban skin consists of a chromatophoric unit. "Chromatophore" in this case is just an umbrella term for the melanophores, iridophores, xanthophores, erythrophores which contain the different pigments.

[Sandra Panienka]

Ok, now I understand what you wanted to say, no worries. :O) And yes, the amphibian skin's chromatophoric unit also contains iridophores.

[Sandra Panienka]

As far as I know Pelophylax spec. and other Ranids (at least Rana catesbeiana and Rana clamitans, 'cause they were covered in several papers) don't have cyanophores. Papers on that topic are actually quite cool.
Wiki says that the dendrobats have cyanophores, but I never digged into that paper-wise, that is something I have to catch up with at some stage.

We tried to get into that stuff in this thread started by Pierre-Yves: viewtopic.php?f=9&t=1162

[Jeroen Speybroeck]

We tried to get into that stuff in this thread started by Pierre-Yves: http://www.fieldherping.eu/Forum/viewto ... f=9&t=1162

And still no answer for the arvalis blue...
But =>
http://www.fieldherping.eu/Forum/viewto ... 726#p11726

[Matthieu Berroneau]

Intersting discussion.
Juste on question (perhaps a big mistake : is yellow color due to pigments ? (not only remains toxic elements ?)

Ps : a leucistic Pelobates if I don't make mistake...

[Sandra Panienka]

We tried to get into that stuff in this thread started by Pierre-Yves: viewtopic.php?f=9&t=1162

And still no answer for the arvalis blue...
But =>
viewtopic.php?f=9&t=1162&p=11726#p11726

Yeah, I think that was the paper (first link). The Glandt paper has a nice picture (Abb. 5) which looks like there is an increase of the pigments in the melanophores (animal turns darker) and than there seems to be a stage were the iridophores dominate over the other chromatophores (animal turns blue).

I have a couple of papers of which one was particulary interesting, but I have to cross-read them to figure out which one it was, something tells me the last one, but I'm not sure:

Forbes, M.S.; Zaccaria, R.A. and Dent, J.N.: Developmental Cytology of Chromatophores in the Red-spotted Newt. Am. J. Anat., 138: 37-72 (?)
Pederzoli, A. and Trevisan, P.: Pigmentary System of the Adult Alpine Salamander Salamandra atra aurorae (Trevisan, 1982). Pigment Cell Research 3: 80-89 (1990)
Pederazoli et. al 2003: Xanthophore Migration from the Dermis to the Epidermis and Dermal Remodeling During Salamandra salamandra salamandra (L.) Larval Development. Pigment Cell Res 16: 50-58

@Mattieu: As far as I know yellow pigments are build in the xanthophores, never read anything about toxic substances anywhere.
I would not call the Pelobares leucistic as there are still yellow pigments and darker pigments left, but I can't really see the color of the darker pigments, is it reddish or brown?

[Matthieu Berroneau]

Thanks !
For this precise case, I think that it's not due to disease, because I some specimens like this since always on this spot.
It's seems to be a local trend...

For example this one :









And maybe the more strange...



Matt