Panaque schaeferi is a freshwater species of fish from the Loricariidae family of South American armoured catfish. Panaque schaeferi is widely distributed throughout the upper Amazon (Solimões river) in Peruvian and Ecuadorian rivers, and has been observed as far down as Santarém, Brazil. Growing to at least 600mm SL, it is one of the largest, and likely heaviest species of Loricariid.