Eat dirt.

We humans prefer to chew chewing gum, or some other stuff which probably isn't to good for your health (or maybe addicting...). Some fish just like to chew upon some heavier stuff, like gravel! Valenciennea eats dirt. The grudgeons chew upon it, spit out the real dirt through their gills trying to keep anything eatable within their mouth. A great thing to obseerve in an aquarium. It will surprise anyone who never has seen this behavior before. To the Valenciennea it is simply a matter of survival.
So...anyone in for a Gravel Burger?

P.S. Valenciennea comes in a wide variety of colors. Most species have a rather dull greyish body with vertical bars in red, ore brownish red. Some however show great coloration, like this Valeciennea strigata, well known for its striking yellow head, with blue iridescent stripes.