Concave plastron - is it normal

[Emmet’s Raph]

Raph is 8 months old now and in the last month have noticed his plastron is getting concave, the back half, but with a center ridge. Just concerned if this is normal

 

[Yvonne G]

He probably could do with a little more moisture in his enclosure.

 

[Emmet’s Raph]

Thank you