Pterygoplichthys

Genus of fishes

Pterygoplichthys, sometimes collectively known as janitor fish, is a genus of South American armored catfishes. These fish are commonly known as sailfin armoured catfish or sailfin plecs, especially in the aquarium trade.

Pterygoplichthys is derived from the Greek πτέρυγ (pteryg ), meaning "wing", (hoplon) weapon and ἰχθύς (ichthys) meaning "fish".

Pterygoplichthys has undergone much shifting in the past decades. Previously Liposarcus, Glyptoperichthys and Pterygoplichthys had been named as separate genera. Since then, these genera were recognized as synonyms of Pterygoplichthys by Armbruster, as the few differences between the genera were not deemed great enough to validate Glyptoperichthys and Liposarcus, and that recognizing these separate genera would leave neither Pterygoplichthys nor Glyptoperichthys as monophyletic.

Pterygoplichthys can be differentiated from most other loricariids due to their large dorsal fins with 9 or more (usually 10) dorsal fin rays, which gives them their common name "sailfin catfish". These fish have rows of armour plating covering the body; the abdomen is almost completely covered in small plates. These fish have been introduced into many locations. Several species of Pterygoplichthys have been established in the United States in Florida, Hawaii, Nevada, and Texas. Sailfin catfish are one of the more successful established exotic fish in Florida in terms of their range extension and abundance, yet their presence has not had any measurable effect on native fishes, although they have contributed significantly to the carrying capacity of some fish communities. Moreover, none of the 30 professional water managers, engineers, lake management, and shoreline stabilization company owners contacted in 2004 by a particular study considered erosion caused by the burrowing activity of loricariid catfishes a major problem, except in some man made lakes in the southeastern part of the state. In Mexico, P. multiradiatus is established in Campeche, Chiapas, and other localities in central and western Mexico, while P. pardalis has been found in southeastern Mexico. In the Philippines, where these fish are known as janitor fish, P. disjunctivus and P. pardalis have been found, these fish are considered a threat to the freshwater fish population; they are found in the Marikina River, Laguna de Bay and the Pasig River. P. multiradiatus has also been established in Puerto Rico and Taiwan. In 2022 Hungary the species was first discovered in Lake Hévíz. After catching an documenting several more specimens the species could be identified with certainty. It was also established that the species has successfully colonised he lake and has been declared an invasive species. [1]

Their primary food is plant matter. Their diet consists of algae, aufwuchs, general plant matter and possibly carrion. They are grazing animals or scavengers as opposed to predator fish. Pterygoplichthys are known for being kept out of water and sold alive in fish markets, surviving up to 30 hours out of water. Males excavate tunnels into mud banks where eggs are laid.

P. gibbiceps has been bred commercially in fish farms in Florida and Malaysia for the aquarium trade. P. multiradiatus and P. pardalis are both known as common plecos and are widely sold as algae eaters. However, most of them grow too large to be housed in an average home aquarium. In fact, in the wild, the Common Pleco can well exceed 2 feet in length, and, as well as growing large, they also produce a lot of waste that can pollute the water.

Pterygoplichthys is an exact anagram of Glyptoperichthys.