Well, I bought him a couple months ago with that coloration (very different, darker substrate) and it hasn't changed at all. The one still at our LFS has pretty much exactly the same coloration as well. And our LFS uses different foods than we do. It makes me wonder if there is some other factor ...

Thanks for all of the responses. So does anyone know what exactly causes the dark yellow coloration?

Sold as a "yellow" S. shoutendeni. Looking through the Cat-E Log I see nothing that looks exactly right. Any ideas? http://www.deadwarrior.com/downloads/pictures/fish/synodontis_1a.jpg http://www.deadwarrior.com/downloads/pictures/fish/synodontis_3a.jpg http://www.deadwarrior.com/downloads/pictures ...