ive had 2 upside down catfish for about 3 months. suddenly one of them has lost the brown markings and has become a sort of creamy colour. is there somthing wrong with it?
I have the same with one of muine, a sort of chameleonic quality.
I believe it is a sign that they are hungry. A few pellets always sorts mine out.
I've also been told that they are somewhat susceptible to sudden changes in lighting levels. If the light suddenly brightens, they can go all pale. I guess this could also be some kind of chameleonic camouflaging defense mechanism they have.