LionFish acting weird

[swill]

We have a Lionfish in our 300 gallon tank that has been acting strange for the last week or so. We have had him for over a year and he been fine up until now. He swims around in circles, hits his head on the ground, he's very weak and has no interest in eating.

All the other fish look fine and the Parameters are all good. We've had this tank for 2 years and I've been in this hobby for 10 years and have never seen this type of behavior.

I took a video of him tonight so see if anyone has any suggestions on what could be wrong with him.

Here is the link:
http://www.youtube.com/watch?v=XxZIzmNBGfU

Do you think maybe it's a blockage? Any insight would be appreciated.