Why there can't be Blue geckos (Long and boring) =)

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Posted by Ike420 on November 25, 2002 at 10:51:17:

In Reply to: blue crested geckos posted by tom matlack on November 24, 2002 at 16:16:26:

The blue coloration expressed by some cresteds is not actually blue. It can't be. There are three main pigments that control the pigments of most reptiles (undeniably there are sea snakes with true blue coloration). Melanin controls levels of black and other dark coloration, xanthin controls levels of yellow pigment expression and erythrin controls red coloration. There are two different paths to obtain a "blue" animal.
The first path is to increase the melanistic expression of a "green" animal which, I may note, is not actually green at all. The green in crested geckos is a delicate combination of beige controlled by xanthin (yellow) and melanin (black). At times when the melanin is lighter (during color change-perhaps between nocturnal and daytime coloration), the green becomes evident. Color change is a separate category all together. Color change is regulated by chromatophores in the skin that contain cytoplasmic pigment granules. Most geckos only have melanophores to change coloration (correct me if I'm wrong, they could also have xanthophores or erythrophores). Chameleons, on the other hand, have xanthophores and guanophores in a level beneath their melanophores. The guanophores control the blue coloration that chameleons can express. When the yellow xanthophore cells are enlarged overtop of the guanophores, the animal appears green.
BUT THERE IS A HUGE DIFFERENCE BETWEEN COLOR CHANGE AND NATURAL COLOR...i just want to emphasize that. Melanin, xanthin, and erythrin control natural coloration, whereas levels of melanophores, xanthophores, erythrophores, and guanophores control color changing.
The other road to blue coloration takes a light colored animal and gives it a purplish hue that appears blue due to the amelanism of the animal. An example of this is the blue gecko pictured at www.crestedgecko.com (follow the link below). This otherwise white animal has a combination of melanin and erythrin, lightened by xanthin that has given it a bluish/purple tint. This is about as close to true blue as one can get. The picture I posted earlier of the blue female and the picture above are geckos which use the first route, where they are only blue during the daytime due to decreased levels of melanin. Follow the link to the other type of Blue crested.

:hello all
:i have a question for everyone. me and a freind are looking for blue cresteds. does anyone know who is breeding this phase?? is the blue a natural color or the result of years of line breeding different colors to obtain the blue color?? one last question anyone have any idea how much the blue ones are going for?? ive heard that they are like $3000 a piece which seems crazy but is that price correct?? i emailed sandfire ranch about these but allan is in australlia till dec. so i figured id try here. lol
:thanks
:tom

CrestedGecko.com's Blue gecko

Follow Ups:

Re:Beautiful geckos raccaboo 11/25/02 (0)
why can't there be blues or a gap in literature jff 11/25/02 (1)
- In agreement... Ike420 11/25/02 (0)
Darn...... Silly-atus fan 11/25/02 (1)
- Green kingsnake Ike420 11/25/02 (0)
good answer and info...... mikecoscia 11/25/02 (0)