Do you have QT tank ready to go?
Also, gigs need to attach to the rock, typically near the rock/sand interface. Ordinarily, I would advise to move it to a more a suitable location, but beacsuse I am confident you will need to treat, that is not a good idea. In the meantime I'd place a rock near him that he can attach to but that you can easily remove when necessary.
Is that the same nem in the basket? How old is your tank? Whats your flow look like?
My sand can't even stay on my sandbed let alone a blob of water.
Any update today?
Hate to say it but it's probably dead or close to it, judging from the pics it didn't look very healthy or happy.
If treatment began it could bounce back.