Hypostomus plecostomus, the suckermouth catfish or common pleco, is a tropical fish belonging to the armored catfish family (Loricariidae), named for the armor-like longitudinal rows of scutes that cover the upper parts of the head and body (the lower surface of head and abdomen is naked). Although the name Hypostomus plecostomus is often used to refer to common plecostomus sold in aquarium shops, most are actually members of other genera.