I adopted a hermit crab who was being kept in typical negligent care conditions two days ago. He was in a very small kritter keeper with gravel, pellet food, and no water dishes (just a sponge) or calcium. He is very active and has so far eaten very well, but his exo is extremely pale colored for a purple claw. Is this a sign of ill health? Poor exo? He's just much lighter than my other (healthy) crabs so I'm a bit concerned.