Yellow Tang

[mbeach66]

i've had my tank extablished for a while now and noticed that during the night my yellow tang loses its bright yellow color and developes a darks spot on its side. it goes away in the morning. i was wondering if anyone else has encountered this, and is it anything to be concerned about?

MBEACH

[tilla]

Same thing happens to mine... Not sure what causes it but he seems pretty happy once the light goes on...