Harlequin At 45deg Angle In Dim Light

[corradophil]

One of my Harlequins is showing some strange behaviour.

During the night my tank light is off, the fish are in darkness.

If I close the curtains in the room they are in, when I open them in the morning one Harlequin floats near the bottom of the tank over a small peice of driftwood and when viewed from the front he is at a 45 degree angle (leaning sideways), from the side he is horizontal (Normal). If I switch the tank light on, within a couple of minutes he's back to normal swimming around happily, and not leaning over.

If I leave the curtains open all night he's fine without the tank light on.

Can anyone tell me why he's being affected by the light in this way? Should I be concerned?

 

[TylerFerretLord]

He may just be sleeping.

If you keep the curtains open, natural light probably wakes him up before you notice his drifting.

IMO, nothing to worry about, but you may want to wait for other more experiance people to post just to be sure.

 

[corradophil]

He may just be sleeping.

If you keep the curtains open, natural light probably wakes him up before you notice his drifting.

IMO, nothing to worry about, but you may want to wait for other more experiance people to post just to be sure.

Good point, I hadn't even considered that, certainly seems fine and normal at all other times.