Odd markings

[FIN-ITE 34]

Today I fished Satan's Pit. Water was low as to be expected but was extremely cold. I came away with dozens of browns and two brook trout with just about every brown looking like the attached photo. They had light and dark patches that appeared in every way to look like healthy tissue on both the light and dark patches. Curious if anyone else has seen similar or if they may know what causes this.

 

[Rusty Spinner]

The only time I can recall seeing that is when they are dying like this one. But this one had talon marks in it from an osprey or eagle and was in fact dying a slow death. It's weird that you caught a bunch like that.

 

[FIN-ITE 34]

Seems the brown trout has the ability to vary coloration to match its habitat for camouflage.

https://nationaltroutcenter.org/learn/biology-and-ecology/

Makes sense as that stream has a varied gravel and rock bottom with the rocks being either clean or covered with a dark green moss.

 

[golden beetle]

Do markings and coloration change during the lifetime of the fish?

Or perhaps do markings develop to match the environment?

I’ll read the article you attached. Very interesting.