Powder blues/goldrims eat by scraping?

[MandarinFish]

Do acanthurus eat by scraping with their teeth?

I saw a powder brown? / goldrim eating an algae sheet by scraping it, rather than tearing it like most tangs.

I have also seen a powder blue eat microalgae by scraping it off glass, also never seen another tang eat micro or by grazing.

Has anyone else seen this behavior before?

 

[wade1]

Most tangs do scrape, although they learn to "suck" in or bite chunks out of sheet algae fairly well. The Ctenochaetus tangs are called "bristletooth" tangs because they actually have bristles in their mouths and do not eat like the other tangs. They can sift sand or cruise along picking up detritus and algae easier than the other tangs do...

Wade

 

[MandarinFish]

hmmm...

so have you seen a powder blue scrape microalgae off of glass before?

Is that unique to the specimen I observed?

 

[tanzy]

My purple tang pecks at the glass sometimes, especially if there is green algae. I'm not too sure if it's algae or pods it's eating.