Tangs and substrate

[Vette67]

I was wondering what the consensus was on the importance of substrate when keeping tangs. In particular, my lavender tang is a regular consumer of my arragonite substrate. He nips at the gravel regularly. And it is even apparent when he poops, you can clearly see the gravel in there. I have notice my other tangs pick at the gravel as well, but none as much as my lavender tang. So in the case of people with bare bottom tanks that also keep tangs, are they missing a beneficial part of the digestive needs of tangs? I am not considering going bare bottom, but was just wondering how important gravel is to them. I’m assuming they use it in their gut to further grind food to aid in digestion. And I’m further assuming this is a fairly normal habit for tangs.

Has anyone studied this?

 

[Ike]

Some tangs are also detritivores and will consume a fair amount of detritus and more slime like algaes that coat substrates. Ctenochaetus is know to consue a lot of detritus. Your tang could also just be getting morsels of algae and is getting a little substrate with it.