Hello everyone. I have recently noticed that my Hermann Tortoise Rocky has a white line on in area of his shell. I have read about growth rings and I am assuming that's what this is but I just wanted to make sure because better safe than sorry. Here are the photos I for some reason it didn't work when I tried to upload them through here. The first picture is a couple of months ago (Before) and the second picture is today (After). Rocky is either 3 or 4 years old and is 5 inches last time I measured him which was a couple of months ago. Any responses are much appreciated.