I got my young sul tortoise. He/she seems to have these sort of black spot/ scab type thing on the undershell. It's slightly softer than the rest of the shell so I am slightly concerned. I can't find any info on it. It seems to be doing well so far. has good energy eats pretty well, rest of the shell is great but I am worried this might be an issue further down the line. I keep him in a big tortoise table with 3 substitutes (sand, straw & coco soil) I always feed on the soil never the sand. Any help / tips would be most welcome