Bizarre Clown Behaviour

[pisces01]

I have an 108 g reef tank with, as of last Saturday, 2 young percula clowns. One Clown is quite aggressive towards the other. When the aggressive one swims at the other, the less aggressive one sort of has a little (what looks like) attack. He shudders for a couple seconds. I read on a previous post that this shaking may have something to do with mating??
They both appear to have excellent appetites becuase they seem to be constantly looking for food - does this mean I'm not feeding them enough? Right now I'm giving them, on alternating days, a frozen reef formula or flakes.
So anyways, there's more. Last night when the lights went out in the aquarium the guy who does the shaking thing started swimming on his side near the top of the water. The other one was in their regular corner near a powerhead. I turned the lights in the room back on and it seemed to calm him down and he went back down and started swimming with his partner again.
Does anyone know what's going on here?
Are levels are all decent (ammo 0, Nitrie 0, Nitrate 10, pH 8.2, salinity 1.023)
Thanks!!
[ May 22, 2001: Message edited by: Pisces01 ]

 

[b_ball12_99]

I have noticed with my FW tanks that when fish swim sideways they usually end up dieing. Do have a red tiger barb that stays vertical (strange I know). He is vertical so he can hide behind plants from the other one because it is aggressive to it.

 

[pufferlover]

Pisces; I have had clowns that do that same thing at night sort of laying to one side at the top of the water line. I have never noticed a problem with them doing that as they do sleep in some strange ways. I have some that would go up behind the power filter inlet and sleep there. If once the lights are on it acts naturally then I would say it just has its own way of resting.