Can plecostomi eat while sleeping?

[Plecostomus129]

I was watching my common plecostomus, and I noticed that he is always eating. I was just curious as to if they could eat in their sleep, because mine always seems to be eating, and you cannot tell if they are sleeping very easily due to their lack of eyelids.

 

[NYgiantsRP]

I have never seen any fish sleep...I was under the impression that they didn't sleep..haha