Black spot on Yellow Tang

[Tbremer]

Last night after the lights went out I saw that my yellow tang had a very large black spot on both sides of his body. It seemed to go away after i turned the lights back on. Not sure if this is a problem or just occurs naturally

 

[NC2WA]

could it be the "false eye" that fish have?

 

[leebca]

Tangs are known to alter the hue and colorations with mood. After the lights go out, they often change hues or color patterns to become less visual in the dark.

Just be sure that when the lights go back on and then a few hours later, the spots are gone. If they are still there, please take a photo and let's what it looks like.

 

[Tbremer]

yea the color returned even after a few minutes