I have a Golden Chinese Algae Eater that is about 5" now and has been very healthy and active since I got him. In the last week or so though he has gone from completely gold to getting this brown/black discoloration on his scales. It doesn't seem to me like it is a growth on the scales but more like a change in color. Is this natural or is this cause by a lack of or too much of something?
Here is the one picture I took but if someone wants a better or different picture I can take another.