Frogfish maybe swallowed air?

[fishoholic]

I noticed my frogfish looked like he was floating to the top of the tank the other day, once he got to the top he'd dive back down to the bottom, only to float up again. Wasn't until he was able to move under the marco algae in the tank that he stopped floating around. I've heard of frogfish doing this when they've swallowed air, but my frogfish has been in his 10g tank for a few months now and was never exposed to air. He also hasn't eaten in the past 4 days which is very unusual for him.

I read about holding the fish by it's tail so it's mouth is facing upwards and when they fight to get away it sometimes releases the bubble. Tried this last night and he puffed himself up and opened his mouth really wide and thrashed around a bit, which freaked me out, so I let him go. Never saw a bubble come out and unfortunately because it freaked me out, I didn't try for to long. Right after that he dove down to the rocks and looked a bit better, but then shortly after that he was floating around again until he went under the marco algae.

I also read about massaging it's belly until it burps the bubble and/or whatever else out. However his mouth is pretty close to his belly so I will have to work up a lot more courage before I try that.

The odd thing is his belly doesn't really look bloated, like I think it would, if there was an air bubble in it. Which makes me wonder why on earth he's floating around and not eating, which are signs of air being swallowed. He's in a 10g by himself so it's not like he's being harassed by any other fish or anything like that. The only other thing I can think of is maybe he ate a stomatella snail? There are lots of those in the tank, most of them are pretty tiny but there are a few big ones. I haven't tested the water parameters in awhile but the coral looks ok and I do 10% weekly water changes so I don't think it's a water quality issue but I'll test and check my nitrates etc. later just to make sure.

Any thoughts/ideas? Anyone have anything similar that they went through with their fish?