I’ve found they don’t actually make mucous cocoons like the Fairy and Flasher Wrasses are known for.
They don’t use the sand either, instead they just tuck themselves into a secure crevice that they feel safe in and sleep in there.
Yeah that’s what mine does too, he has a crevice in the rock work he sleeps in every night!
To the original poster, I also have one and he hid for quite a while before I finally saw him cruising around the back side of the tank, but then once movement was detected he’d hide again. Now that he’s been in there a long while…well adjusted and acclimated, he’s been out and about a lot more but still would retreat into the rock work when I came over to the tank.
He’s actually out even more now since I added a wild caught yellow assessor recently (last week) who has literally been out and about since the moment I put him in the tank. That guy is unusually bold for an assessor so I think that the assessor being out and about all the time gave the pink streaked a little more confidence to come out and stay out without retreating into the rock work.
I got super lucky with my Pink Streaked, he was at my LFS marked/sold as a 6-line wrasse for $45!! He'd apparently been there for a couple of weeks when I was on vacation and didn’t swing by the shop….he was eating well and looked super healthy….don’t know how no one had grabbed him…but as soon as I saw him in the cubicle I knew exactly what he was and was like SOLD!! My LFS literally never has them in the store.
I only have 3 fish in my 20 Gallon Nano tank at the moment as I’m getting ready to upgrade to a larger tank.
Pink Streaked Wrasse
Yellow Assessor
Geometric Pygmy Hawk
But I’m in the camp of he’s probably totally fine and hiding out getting acclimated!!
The one thing I would mention is these are very shy and peaceful fish that don’t typically handle bullying very well, and you do have some larger more boisterous fish on the stock list in your tank. So that being said it may take him a little longer to feel confident and comfortable being out and about.