Radiata hatchling worried about Bottom shell

[Arcachinny]

Hello,

I have 2 radiated hatchlings approx 6-9months old and one of them shows weird coloring on bottom shell like it would be whiting out/losing black pigment, not sure how to explain better but have attached photo of both to see the difference, they are kept at same enclosure together. Could this be related to some sickness or vitamin deficienty? Any suggestions or experience is welcome as I am starting to worry about the one even though he/her is active and eating well, thanks.

 

[Tom]

They both look a bit too dry, but I don't see anything else out of the ordinary.

Tortoises should never be kept in pairs. Separate them, or get a third one to make a trio, or more.