Coloration/toxicity question

[edward]

Typically the ones I have at home showed an intensification of the blue in the tail.

Ed

 

[joseph]

I haven't seen any pics or any C. o in life with blue on the tail. perhaps you just have very brilliant C. o

 

[edward]

Plowing through Amphibian Biology Volume 1 The Integument I hit a section on coloration in amphibians. According to the information in the book reds and yellows are not always due to caretenoid sequestering. A second group of colors derived from purines (presumably guanine) are known as pteridines. Drosopterins and pterorhodin are both red.
This may be an indication that the loss of color in some species of caudate is not due to a lack of caretenoids in the diet but some kind of disruption in the pterin pathway (for a far fetched example, exposure to cues from predators are required to shift resources to the drosopterins metabolic pathway). (In Bombina, there are apparently both caretenoids and pterins present in the ventral coloration.)
Or it may be possible that there is excess synthesis of yellow pigment washing out the red.
The inforamation is slightly outdated but interesting.
(There is also some information on how to determine if a pigment is a pterin or caretenoid).

Some thoughts,

Ed

 

[benjamin]

Couldn't the green back colouration of Triturus Maromatus simply be camoflauge, that would make the newt difficult to see from the side or above when in densely planted surroundings on land or under water. Also the light but dull colour of T.maromatus's belly could also help the animal camoflauge against the surface of the water, like counter shading. I think these two newts (Cynops sp, and T. Maromatus) tackle the art of survival in different ways, one blends in, while the other stands out.

 

[edward]

Hi Ben,
My original comment on Triterus was for breeding displays.
Many aquatic species use countershading as a defense (such as Notopthalmus).

Ed

 

[jesper]

Very interesting discussion!