Marmoratus colour change

[william]

I've just noticed on my marmoratus, that in two of my newts the green has become darker and bluer, the colour i'd expect from pygmaeus while the other has stayed bright green. the colour of the stripe has not changed at all. can anyone explain this?

 

[mark]

Hi Will, I think it’s normal for colour change to occur in marms, especially as they age. I too have individuals who have taken on a blueish green as they mature. Juveniles tend to be brighter coloured. In many cases this may represents toxicity levels which can be higher in young animals (Notos, for example in the red eft stage) however I’m not sure if this is true for marms. Other considerations include light exposure, hormonal and environmental factors which have all been shown to affect chromatic behaviour.