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

A demand exists for them as a bottom cleaner in the aquarium trade. These fish are sold when they are young and small, but they can grow to be a maximum size of 50 centimetres (20 in).