One of them is dancing around the tank (a good sign

I went to this LPS a couple of days ago & saw 3 loaches.
Today, I only saw 2.
I asked the salesperson what happened to other one & she doesn't know.
*hint: make it a habit to visit the LPS a few days later to see if the same fish is still doing ok*
In the LPS, one was always the active one, whereas the other was quiet & hides.
The quiet one still stays quiet when I brought him home.
He hardly swims around, sometimes staying near the surface with his body almost vertical

I'm real worried.
At times, he's so still that I thought he was dead


I had to stroke him to make sure he's alright!
Also .. when I look at both of them under the light, their body seems to be almost transluscent & I can see their bones

Is this normal?
Is the quiet clown just acclimating?