Looks like water bubbles on skin???

[ydarr]

We purchased a Copperband Butterfly about 1.5 weeks ago strictly for eating some Aptasia that grew in our newly set up 24 gallon tank. The fish seems to be fine in terms of eating and swimming around. Today we noticed his skin looks like it has water bubbles on it. What is that? Should we worried? Also, all we have in the tank is live rock, sand, 1 tiny candycane coral, small zenia and another small coral that at this time can't remember the name. Please help!