My adult bristlenose (from breeding pair) is acting very strangley and I'm worried about him. Normally he's in his little castle ornament (his territory and breeding ground) and won't even leave it if I lift it out of the water. We've just moved house and I've separated him from the female for a while and put him in my 29 gal. He's now spending all his time at the top of the tank on the glass and keeps leaping up at the surface from his position and gulping air. He also looks bloated. Normally I would immediately assume there is a lack of oxygen in the tank but the other fish in there are fine. What can I do? Any ideas what might be causing this?