Amazon Sailfin Catfish, Pterygoplichthys pardalis
Amazon Sailfin Catfish, Pterygoplichthys paradalis. Fish caught from the Gila and Salt River Confluence, Tolleson, Arizona, August 2020. Length: 27 cm (11 inches). Catch, photograph and identification courtesy of Chris Moore, Peoria, Arizona.
The Amazon Sailfin Catfish, Pterygoplichthys paradalis, is a member of the Suckermouth Armored Catfishes or Loricariidae Family, that is known as the Common Pleco and Leopard Pleco and in Mexico as plecóstoma del Amazonas and plecostoma leopardo. They are native to the Amazon River Basin of Brazil and Peru. The Loricariidae Family is the largest catfish family with 680 recognized species. Globally, there are sixteen species in the genus Pterygoplichthys, four of which are found in the freshwater systems of mainland Mexico.
The Amazon Sailfin Catfish has an elongated and easily recognizable “catfish-like” body with an inferior suction mouth and two maxillary barbels on the ventral side. Their heads have a geometric pattern and the ventral side is covered with leopard-like dark spots that vary in size. Their adipose fin has 1 spine, their anal fin has 4 rays; their dorsal fin has 1 spine and 11 rays; their pectoral fins have 1 spine and 6 rays; and their pelvic fins have 1 spine and 5 rays. Their heads have subterminal mouths. They adults possess several anti-predatory adaptations including external bony plates, deep bodies, long sharp dorsal and pectoral fins that can be locked erect in place and they have the ability regenerated appendages such as pectoral fins. The juveniles lack the full development of the above and are subject to heavy predation and limit their feeding activities to night time hours. They reach a maximum of 49 cm (19 inches) in length and 0.3 kg kg (0 lbs 11 oz) in weight.
The Amazon Sailfin Catfish is found in shallow waters along the shoreline or within soft or rocky beds of slow-moving stream with water that is clear and can be polluted that are between 23oC (73oF) and 28oC (82oF). Mature fish are known to move to shallower, brackish waters after storm flooding with mesohaline salinities (8 – 13 ppt). They can be found primarily in coastal waters but also in streams at elevations up to 3,000 m (10,000 feet). They have the ability to survive in low oxygen environments being capable of breathing air from the surface of the water during dry periods. The males dig out river banks to create burrows in which the females will lay, then guard her eggs and then rear her family. They feed by grazing on algae and on benthic organisms and detritus. In turn they are preyed upon by various fishes including the Common Snook, Centropomus undecimalis, and Tarpon, Megalops atlanticus as-well-as sea birds including Neotropic Cormorants, Phalacrocorax brasilianus and Osprey, Pandion haliaetus. They have life spans of 5 years. The Amazon Sailfin Catfish is poorly studied with very limited information available about their lifestyle and behavioral patterns including specific details on age, growth, longevity, movement patterns, diet, habitat use, and reproduction.
The Amazon Sailfin Catfish can be distinguished from the North American Catfishes of the Ictaluridae Family via its ventral mouth. They are often confused with Hypostomus (7 or 8 dorsal fins). They are most likely confused with the Vermiculate Sailfish Catfish, Pterygoplichthys disjunctivus (abdomen with vermiculate worm like patterns).
The Amazon Sailfin Catfish is native to the Amazon River basin of South America. They have been widely introduced in several countries outside their native range, predominantly by aquarium releases, and first showed up in Mexico in 1995. They have been documented in freshwater systems of the states of Chiapas, Guerrero, Michoacán and Tabasco. It is more than likely that due to their high level of invasiveness they will be currently present in several other locations.
From a conservation perspective the Amazon Sailfin Catfish has not been formally evaluated. Due to their highly invasive nature they have become or will soon become pests in several locations where they have been introduced. They have proven to be very difficult to eradicate. They generate a large amount of silt, destabilize river banks by their nest building which increases erosion, and disrupt aquatic food chains. They are utilized by the aquarium trade and are in high demand due to their visual appearance and their abilities to remove algae from the environment. They are consumed as a human food in some regions.