Pyrrhogaster Belly Markings

[Mark]

I was making some shots of Cynops pyrrhogaster Sasayame bellies today. The two on the left are male and the two on the right are female. At what age do females develop the classic speckled markings like the one on the far right? There seems to be quite a bit of variation within related animals. Do other races have such well defined marking differences between sexes?

 

[evut]

The pattern on one of my females, less than 2 years old, is starting to change already - there is a lot less orange than before and small white specks are appearing in the expanding black parts.

 

[Viv]

I love the belly of the 2nd and 4th pictures. Haha