That's bs. I have never seen a pleco with out those. I know not a single lfs in my area would condone that practice. Quite sure that would do a lot of damage to the pleco possibly to the point of death and why would you risk that for so frivolous a thing. Now on the other hand if you are going to have a pleco that is "bad" that is what they'll do the most damage with to other fish and or you. I have a bristle nose that will kill any other pleco it's with and most other catfish too. It uses the cheek spines and the pectoral spines to stab the other fish.