Identification: Weber (1991, 1992) assigned sailfin catfishes to three genera. Armbruster (1997), after a detailed systematic review, placed the genus Liposarcus into the synonymy of Pterygoplichthys. Weber (1992) provided a key and distinguishing characteristics and photographs of specimens; Armbruster and Page (2006) present a revised key to species in the genus Pterygoplichthys (except P. ambrosettii).
Pterygoplichthys and other suckermouth armored catfishes (family Loricariidae) can be distinguished from native North American catfishes (Ictaluridae) by the presence of flexible bony plates (absent in ictalurids) and a ventral suctorial mouth (terminal in ictalurids). Pterygoplichthys is often confused with Hypostomus: these genera can be distinguished by the number of dorsal fin rays (7-8 in Hypostomus vs. 9-14 in Pterygoplichthys).
Ecology: Pterygoplichthys spp. can be found in a wide variety of habitats, ranging from relatively cool, fast-flowing, and oxygen-rich highland streams to slow-flowing, warm lowland rivers and stagnant pools poor in oxygen. They are tropical fish and populations typically are limited only by their lower lethal temperature, which has been found to be about 8.8–11 °C in some species (Gestring, 2006). They can thrive in a range of acidic to alkaline waters in a pH range of about 5.5.0 to 8.0 (Mendoza et al. 2009). They often are found in soft waters, but can adapt very quickly to hard waters. Pterygoplichthys spp. also are highly tolerant to poor water quality and commonly are found in polluted waters (Chavez et al. 2006). They are known to use outflow from sewage treatment plants as thermal refugia and can readily adapt to changing water quality (Nico & Martin, 2001). Some species are salt tolerant (Mendoza et al. 2009).
Freshwater; demersal; Tropical; 21–24 °C (Froese and Pauly, 2012). This catfish primarily is a detritivore, but it also feed on benthic invertebrates and algae. Like other members of this group, it digs burrows for nests (Nico and Martin, 2001)
Impact of Introduction: Largely unknown. In several natural streams in this species is relatively abundant. Because it grazes and removes attached algae, and also feeds on benthic organisms and detritous, this introduced catfish may be having a significant impact on the aquatic food base and, therefore, negatively effecting native invertebrate and vertebrate species (Nico, personal observations).
Male members of the genus Pterygoplichthys dig out river banks to create burrows in which an attracted female will lay and guard her eggs. In large numbers, this burrowing behavior by Pterygoplichthys contributes to problems with siltation. In addition, the burrows potentially destabilize the banks, leading to an increased rate of erosion (Nico et al. 2009). Diurnal aggregations of Pterygoplichthys can potentially alter nutrient dynamics by creating biogeochemical hotspots through nitrogen and phosphorus excretion and remineralization (Capps and Flecker 2013).
References: (click for full references)
Armbruster, J.W., and L.M. Page. 2006. Redescription of Pterygoplichthys punctatus
and description of a new species of Pterygoplichthys
(Siluriformes: Loricariidae). Neotropical Ichthyology 4(4):401-409. http://dx.doi.org/10.1590/S1679-62252006000400003
Capps, K.A., and A.S. Flecker. 2013. Invasive fishes generate biogeochemical hotspots in a nutrient-limited system. PLoS ONE 8(1):e54093. http://www.plosone.org/article/info:doi/10.1371/journal.pone.0054093.
Capps, K.A., L.G. Nico, M. Mendoza-Carranza, W. Arévlo-Frías, A.J. Ropicki, S.A. Heilpern, and R. Rodiles-Hernández. 2011. Salinity tolerance of non-native suckermouth armoured catfish (Loricariidae: Pterygoplichthys) in south-eastern Mexico: implications for invasion and dispersal. Aquatic Conservtion: Marine and Freshwater Ecosystems 21:528-540.
Chavez, J.M., R.M. De La Paz, S.K. Manohar, R.C. Pagulayan, J.R. Carandang VI. 2006. New Philippine record of South American sailfin catfishes (Pisces: Loricariidae). Zootaxa 1109:57-68.
Cohen, K. 2008. Gut content and stable isotope analysis of exotic suckermouth catfishes in the San Marcos River, TX: A concern for spring endemics?. Masters’ Thesis, Texas State University– San Marcos.
Cook-Hildreth, S.L. 2009. Exotic Armored Catfishes in Texas: Reproductive Biology, and Effects of Foraging on Egg Survival of Native Fishes (Etheostoma fonticola, Endangered and Dionda diabolic, Threatened). Master in Science Dissertation. Texas State University– San Marcos. 63 pp.
Gestring, K.B., Shafland, P.L. & Stanford, M.S. 2006. The status of Loricariid catfishes in Florida with emphasis on Orinoco Sailfin (Pterygoplichthys multiradiatus). Abstracts for the 26th Annual Meeting of the Florida Chapter American Fisheries Society.
Mendoza, R.E.; Cudmore, B.; Orr, R.; Balderas, S.C.; Courtenay, W.R.; Osorio, P.K.; Mandrak, N.; Torres, P.A.; Damian, M.A.; Gallardo, C.E.; Sanguines, A.G.; Greene, G.; Lee, D.; Orbe-Mendoza, A.; Martinez, C.R.; and Arana, O.S. 2009. Trinational Risk Assessment Guidelines for Aquatic Alien Invasive Species. Commission for Environmental Cooperation. 393, rue St-Jacques Ouest, Bureau 200, Montréal (Québec), Canada. ISBN 978-2-923358-48-1.
Nico, L. G., and R. T. Martin. 2001. The South American suckermouth armored catfish, Pterygoplichthys anisitsi (Pisces: Loricariidae), in Texas, with comments on foreign fish introductions in the American Southwest. The Southwestern Naturalist 46(1):98-104.
Nico, L.G., H.L. Jelks, and T. Tuten. 2009. Non-Native Suckermouth Armored Catfishes in Florida: Description of Nest Burrows and Burrow Colonies with Assessment of Shoreline Conditions. Aquatic Nuisance Species Research Program Bulletin 9(1): 1-30.
Weber, C. 1992. Révision du genre Pterygoplichthys sensu lato (Pisces, Siluriformes, Loricariidae). Revue Francaise d'Aquariologie 19:1-36.
This information is preliminary or provisional and is subject to revision. It is being provided to meet the need for timely best science. The information has not received final approval by the U.S. Geological Survey (USGS) and is provided on the condition that neither the USGS nor the U.S. Government shall be held liable for any damages resulting from the authorized or unauthorized use of the information.