odd severum behavior

[1 fish 2 fish]

I have a gold severum, it moves around kind of funny. Not always but when he/she does, it kind of like a jerky forward and backward movement, hard to explain. It's about 1 inch. Ammonia and nitrites and 0.
Any guesses would be appreciated.

[ScottoMacD]

Is it like a spastic moving? Quickly from side to side almost like the fish is saying No?

If it is, don't worry.

All my severums do this when they are protecting or defending an area that they have claimed in the tank.

My breeding pairs both do it at the same time when I have broods in the tank and other other fish start to get too close to the fry.

[dbcb314]

if hes shaking no, then dont worry they all do that.

what else do you have in the tank? maybe hes just tryin to scare someone off.

[1 fish 2 fish]

Really? thats cool, I wonder why they so that. THe only other fish that bothers it is the more dominant severum, but he does it even when he isn't being harassed.

I appreciate the respnses, thx.