Angel Changing Colour Instantly

[Hannahpops89]

So just a random question really to see if anyone can tell me the answer. I've noticed when looking at one of my Angels it can turn on and off its black stripes in an instant: is this some sort of camouflage adaptation? I know they often are pale for a while if stressed but this is different (fades in and out in seconds). I've had my 2 Angels for about 4 years- tried determining their gender and given up.

(Apologies for photo being on side, my fish does actually swim the regular way up )

 

[fluttermoth]

Many fish can change colour, either slowly or instantly. The reasons are a combination of camouflage and communication

 

[techen]

In angels could it not be due to stress as well? I've noticed that when angels fight they normally flare up there colour or loose it. Same with bad water or annoying/fast fish.

 

[snowflake311]

Cichlids and many other fish will change colors to express mood. 

 

[DrRob]

They do indeed lose their stripes with stress, but also to denote submissiveness. I'm pretty sure that they rarely stay the same intensity for more than a few minutes at a time in the ones I've had.
 
Lights on also caused a fair bit of colour changing for mine, but I think that was more a camouflage thing than stress, as they didn't seem otherwise bothered by the lighting change.