Adult "Lasiancistrus" have whiskerlike odontodes on their cheeks which are unique among the Loricariidae. These hair-like odontodes are part of their evertible cheek odontodes; they are very narrow, but appear to be made out of the same material as the other odontodes. Their presence does not appear to be sexually dimorphic, although males may have longer ones. In nuptial males, there are fleshy tentacles on the pectoral-fin spines longer than their associated odontodes, which differentiates it from all genera except "Ancistrus". They are differentiated from "Ancistrus" by the presence of plates along the edge of the snout ("Ancistrus" lack these plates) and by maximally having translucent tentacles on the snout that have odontodes associated with them (in "Ancistrus" there are larger tentacles without associated odontodes coloured the same as the head).