Pterygoplichthys multiradiatus is one of several tropical fish commonly known as Orinoco sailfin catfish, plecostomus (or plecos).

P. multiradiatus is mottled brown/black and inhabits freshwater streams and lakes and in weedy, mud-bottomed canals in its native habitat: the Orinoco River basin in Venezuela.

P. multiradiatus browses on substrate, mainly feeding on benthic algae and aquatic weeds, but will also take worms, insect larvae and other bottom-dwelling invertebrates as food.

One of the large plecos (growing to a maximum of 50.0 centimetres (19.7 in) TL), this species likes solitude, is relatively peaceful as an aquarium fish and does well with cichlids and other big fish, and should be kept in large tanks only and with plenty of rocks and driftwood in which to hide.

P. multiradiatus has been introduced to Taiwan,[2] Puerto Rico,[3] Florida, Hawaii, Texas, India, and Mexico,[4] most likely as the result of escapes or releases from aquarium fish farms.