Question about strange activity with percula clown

[undbulsu]

I have a pair of clowns as the only fish in a Red sea Reefer 450. Just starting out. They went through quarantine fine and have been in the tank for over a month with no issues.

However, at night when the lights go out, I have found one fish at the top of the tank, lying on its side practically motionless. Thought it was dead. Touched it with my finger at it immediately swam to the bottom. Next day it was swimming normally and eating well. Following night the same story.

Sleeping? Some kind of swim bladder problem?

Thanks

 

[Dkuhlmann]

Many of them sleep like that, nothing unusual.

 

[D-Nak]

Many of them sleep like that, nothing unusual.

+1. My perc sleeps in its nem at a 90-degree angle, as if it was standing straight up. Odd creatures we have.

 

[Jrsdaddy]

Agree with everyone else, he was sleeping and you woke him up

 

[grizwalt333]

Mine wouldn't lay on their side but they did frequent the top at night even when hosting in my branching hammer... watch out for power heads and such turning on at night or early morning..

 

[wdyork]

Both of my clowns do the same

 

[ratienza80]

My 2 occellaris sleep at the top by the overflow. Sometimes their tail in would go in but their body is too big to fit. If I don't see one of them in the morning, the first place I'll look is in the overflow box or sump. They also sleep parallel to the surface.