Pterygoplichthys gibbiceps is a species of armored catfish native to Brazil, Ecuador, Peru and Venezuela where it is found in the Orinoco and Amazon basins.
P. gibbiceps shows all the characteristic features of its genus—a large dorsal fin with more than nine rays, prominent nasal flares and a prominent hump or crest anterior to the dorsal fin as well as a substantial base to the dorsal fin. Adult fish easily attain a length of 50.0 centimetres (19.7 in) TL and can live for more than 20 years.
A typical plec shape is shown, patternation consists of primarily irregular largish brown spots on a yellowish backgroung giving a honeycombed like appearance, additional pattern features common to related species may be visible on close inspection. As this fish grows the spots get smaller.
Like most plecs this species is primarily vegetarian though will eat dead animals.
In the wild these fish are found in shoals in sluggish rivers of the Amazon and Orinoco river systems, they also occupy flooded land during the wet season. During the dry season P. gibbiceps will aestivate in burrows around 1 metre long dug into mud banks along the length of a river, egg rearing is also presumed to take place in burrow.
The species name comes from the Latin gibbus—hump and Greek cep—head, a reference to the centrally located ridge. Common names include 'gibbys', leopard sailfin catfish and clown plecs—the juveniles have a comical appearance due to the large and obvious spots.
Ancistrus gibbiceps and Glyptoperichthys gibbiceps are synonyms of P. gibbiceps.