Can you give us some more information about you tank and how you acclimated him to the tank? These questions will allow the members to more accurately evaluate the problem:
How long has the wrasse been in the tank?
What kind of wrasse is it?
How did you acclimate him?
What are the other tankmates?
How long has the tank been set up?
What are the water parameters (Ammonia, Nitrite, Nitrate, SG
, Temp, etc)?
What size tank?
What type of filtration?
I know this seems like a lot of information to provide but it will help us a lot to identify your problem.