Justusfish beat me to it
Hmmmm that is not a good thing although it has only been 24 hours. Can you see him at all. Is he breathing heavy or just staying out of sight? Try soaking all the food in garlic and see if that will bring him out. And hang some nori or green seaweed. You can always soak that as we'll. If that doesn't work i don't know what to tell you. I got lucky with mine as all he does is eat. From the second i put him in the tank he ate everything. Hopefully the garlic will work and he is not sick in any way.It may take him awhile to aclimitize to the tank. Patience with this one may pay off.
Keep us posted
Craig