Suckermouth catfish
(Hypostomus plecostomus)

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 (the lower surface of head and abdomen is naked soft skin).

Although the name Hypostomus plecostomus is often used to refer to common plecostomus sold in aquarium shops, most are actually members of other genera.

Suckermouth catfish are of little or no value as a food fish, although they are at least occasionally consumed over their native range. A demand exists for them, however, as a bottom cleaner in the aquarium trade.

Native range is tropical northeastern South America; it naturally occurs in northeastern Brazil, the Guianas, and Trinidad and Tobago. Confusingly, the name Hypostomus plecostomus (or Plecostomus plecostomus) has sometimes been incorrectly used for several more-or-less similar loricariid catfishes, both in the popular and scientific literature. For example, it has sometimes been suggested that it occurs in southern Central America, but this is an entirely separate species, Hemiancistrus aspidolepis (also known under another synonym, Hypostomus panamensis).