At my place of work there used to be a tiger datnoid on display named george. George is no longer on display and the boss is trying to get one of the workers who already has two Dats to take george home. George is about 11 years old, he has hurt his mouth once and had it fixed with a piece of metal which has since been removed, and he is completely black,( in the right light you can see his stripes faintly) he was always kept in completely fresh water. The person who already has two doesnt think it will work and wants me to take george if it doesnt. What is making him black, and what do i need 2 know to look after hime, he is full grown.