I am pretty new to reef-keeping/saltwater tanks. I figured the best way to start was to purchase used, but that didn't end well as the live rock I purchased was full of bristleworms. I bought a Six-Line Wrasse to take care of them and thought I had done sufficient research on them. A few days after he was acclimated and moved to the tank (120-gallon) I noticed he was stuck under a rock and coated with thick mucus, I made the mistake of confusing the aforementioned mucus cocoon with brooklynella. I ran to my LFS in a panic and purchased medicine for said brooklynella which I had been dosing for the past 3 days. I have taken a flashlight, moved rocks, and done everything I can think of in order to find the wrasse but since he was last seen in the cocoon he's been missing. I have a lid on the tank which has a very small hole in the top so I don't believe he jumped but at this point, I'm not sure where else he could be. Any suggestions as to where he is hiding?