I wouldn't worry too much about the clownfish bobbling up and down and/or stay at one spot. In general, clownfish tend to exhibit unusual swimming patterns/behaviors and usually are not swimming all over the tank constantly like others... Most of clownfish I see (including mine) does the same thing, except maybe during feeding time
.
I would be more concerned if he is not eating though. If he has not been eating at all for two days, he may be bothered about something...(especially if this situation persists). From your message, there is not really much info to base a good advice on.
It is helpful to have some background info regarding the environment, for example
- How old is the tank/size of tank?
- Water parameters? When did you last test your water?
- Info on tank mates and their conditions?
- I assume he eats before, anything changed before this behavior occurs?
- What food do you feed the clown?
Also how does the clownfish look currently? Apart from regular routine maintenance, I would advise watching all of your lifestock closely for any unusual behaviors/conditions...
Lets hope he will be back to his normal self and start eating again.
