Why does many plecos change their colour to yellow?

[Lutt]

I had an discussion yesterday about why some plecos change his natural colour to yellow. And why just yellow?
Some say it's a because of stress, but i dont think that it's why. Parancistrus aurantiacus is one of the most famous pleco who have this transformation. Also Hypostomus luteus is capable to change colour.

But my question is why they do this? Does anybody really know what happens?

[Birger]

Here is a start, you may want to carry on in this thread, keeps the information together.

http://www.planetcatfish.com/forum/view ... =5&t=35868

Birger

[plecoboy]

I would guess they turn yellow to blend in with a sandy substrate to avoid predators.