BN pleco colour change ??

[normc]

Can a pleco change colour depending on the background. When she is sitting om th bottom she seems to have light coloured spots matching the substrate 

[babblefish1960]

I wouldn't suggest that they have the ability to camouflage themselves and disappear with the background. However, they often times have the ability to have the melatonin alter focused on their moods, or condition. We know for example that a dead fish gets very pale, while a breeding fish colours up nicely. An upset fish could tend toward darkness or even stripes that aren't always visible.

The other thing that occurs with interpretation of colour intensity, is the relative colours around the subject. Take an olive green sheet of paper of cloth, hold it across your shoulders and neck, and in the mirror, note the colour changes in your face with this or any other colours that either complement or embarrass the "natural" colour of your skin. Same for fish, it is somewhat a matter of perception.

By and large, I would suggest that if your fish is behaving normally, and eating and looking otherwise very healthy, then you would have nothing to worry about. And plecos, they do that as well.