Bacteria on Mandarin Goby?

Question
I just bought a mandarin goby today that did not have any marks and seemed perfectly healthy in the fish store. Shorty upon inserting it into my tank i noticed a patchy discoloration on the side of his body as if a layer was scraped or burnt off. Its not really cloudy or white, just lighter than than the rest of his body as if his skin has faded. I recently added salt to the tank just before putting the fish in, but can't think of anything else that could have caused this. Is this harmful? If so, how should it be treated?

Answer
firstly you should never add salt straight to the tank, it is slightly caustic and can really do fish some damage. best to mix it with RO water for a good 24hours to let the CO2 and O2 levels balance out before adding it to your tank.

mandarin gobies dont have scales like most other fish, their body is covered with a slime coat. just keep an eye on him and feed him well. if you have trouble feeding him, invest in a turkey baster and load it up with either mysis or brine shrimp and just drop food right in front of him.