Thanks, luckies!

Shell rot? Why do you think he has that?
Is it because the top of his shell looks dry? If so, then it's because he had just been in his little "bathtub" in his tank, which doesn't quite cover his whole shell. When I put him in MY bathtub for his weekly swim, his whole shell gets wet, and looks the same as the rest of the shell that you see there.

Otherwise, please tell me why you think he has shell rot.
I'm worried now!