The Nonindigenous Occurrences section of the NAS species profiles has a new structure. The section is now dynamically updated from the NAS database to ensure that it contains the most current and accurate information. Occurrences are summarized in Table 1, alphabetically by state, with years of earliest and most recent observations, and the tally and names of drainages where the species was observed. The table contains hyperlinks to collections tables of specimens based on the states, years, and drainages selected. References to specimens that were not obtained through sighting reports and personal communications are found through the hyperlink in the Table 1 caption or through the individual specimens linked in the collections tables.

Colossoma or Piaractus sp.
Colossoma or Piaractus sp.
(unidentified pacu)

Copyright Info
Colossoma or Piaractus sp.

Common name: unidentified pacu

Identification: Machado-Allison (1982), who provided most recent revision, recognized two genera with three valid species: Colossoma macropomum, Piaractus brachypomus, and P. mesopotamicus. Many synonyms exist (Machado-Allison 1982).


Size: 90 cm SL.

Native Range: Tropical America. Amazon, Orinoco, and La Plata river basins, South America (Machado-Allison 1982).


Hydrologic Unit Codes (HUCs) Explained
Interactive maps: Point Distribution Maps

Nonindigenous Occurrences:

Table 1. States with nonindigenous occurrences, the earliest and latest observations in each state, and the tally and names of HUCs with observations†. Names and dates are hyperlinked to their relevant specimen records. The list of references for all nonindigenous occurrences of Colossoma or Piaractus sp. are found here.

StateFirst ObservedLast ObservedTotal HUCs with observations†HUCs with observations†
AZ197020003Agua Fria; Lower Colorado Region; Lower Salt
AR199220062Beaver Reservoir; Lower Arkansas-Maumelle
CA198920074Calleguas; San Gabriel; San Pablo Bay; Suisun Bay
CO200620061Middle South Platte-Cherry Creek
FL1974201513Choctawhatchee-Escambia; Daytona-St. Augustine; Everglades; Florida Bay-Florida Keys; Florida Southeast Coast; Lower Choctawhatchee; Lower St. Johns; Oklawaha; Peace; Tampa Bay; Upper St. Johns; Vero Beach; Withlacoochee
GA198720046Altamaha; Middle Chattahoochee-Lake Harding; Middle Chattahoochee-Walter F; South Atlantic-Gulf Region; Upper Chattahoochee; Upper Ocmulgee
IL200420122Des Plaines; Lower Rock
IN200020055Lower White; St. Joseph; Tippecanoe; Wabash; Wabash
IA200220021North Skunk
KS198420042Caney; Lower Walnut River
LA199119921Liberty Bayou-Tchefuncta
MN201620161Twin Cities
MS200320032Little Tallahatchie; Yocona
MO198420032Lower Missouri-Crooked; Sac
MT199419952Flathead Lake; Upper Yellowstone-Pompeys Pillar
NE199820082Middle North Platte-Scotts Bluff; Missouri Region
NV200820081Lake Mead
NH200520051Merrimack River
NY199120052Middle Hudson; Seneca
NC199120096Haw; New River; Pamlico; Upper Catawba; Upper Tar; Waccamaw
OH197420053Cuyahoga; Lake Erie; Lower Maumee
PA199520104Chautauqua-Conneaut; Crosswicks-Neshaminy; Lake Erie; Lehigh
SC199320043Cooper; Lower Broad; Seneca
TX1987200610East Fork Trinity; Lake Texoma; Lower Angelina; Lower Sabine; Medina; North Fork Double Mountain Fork Brazos; Sabine Lake; San Marcos; South Concho; Upper Guadalupe
VA198720063Lynnhaven-Poquoson; Roanoke Rapids; Upper Roanoke
WA199220022Pacific Northwest Region; Puget Sound
WI200220063La Crosse-Pine; Lower St. Croix; Upper Fox
WY200620061Middle North Platte-Casper

Table last updated 6/22/2024

† Populations may not be currently present.

Means of Introduction: These fish were probably aquarium releases, although some records may represent escapes from fish farms.


Status: Reported from at least 17 states including Arizona, Arkansas, California, Florida, Georgia, Indiana, Kansas, Louisiana, Missouri, New York, North Carolina, Ohio, Oregon, South Carolina, Texas, Virginia, and Washington.


Impact of Introduction: The impacts of this species are currently unknown, as no studies have been done to determine how it has affected ecosystems in the invaded range. The absence of data does not equate to lack of effects. It does, however, mean that research is required to evaluate effects before conclusions can be made.


Remarks: All reports represent collections of single fish by anglers except where indicated. All Texas pacus but one (the Medina River fish) were seen and identified by Texas Parks and Wildlife Department fisheries biologists (Howells et al. 1991). Because most state fish and wildlife agencies do not maintain records of foreign fishes, many additional captures probably have gone unreported. A newspaper account of a piranha taken from the Lehigh River near Easton, Pennsylvania (Anonymous 1995), was most likely a pacu based on the reported fish size. In addition to the above unidentified pacus, there are at least two cases of what are apparently hybrid pacu, Colossoma macropomum x Piaractus sp. (L. G. Nico, unpublished data; also see Logan et al. 1996). One of these was taken in Oregon from the Snake River near Ontario State Park in Malheur County, on 19 July 1991 (Logan et al. 1996; museum voucher OS 13217). The other was taken in Florida from the Pompano Canal in Pompano Beach, Broward County, in December 1991 (museum voucher UF 96235). A pacu taken with a gill net from the Columbia River in Oregon in 1990 was originally identified as Colossoma macropomum by Logan (personal communication), but that fish was later treated as an unidentified Piaractus, possibly P. brachypomus by Logan et al. (1996). Brazilian aquaculturists have successfully produced hybrid pacus in captivity and a similar practice is likely taking place in some U.S. ornamental fish farms (M. Goulding, personal communication)


References: (click for full references)

Anonymous. 1987. Piranha found in San Joaquin River. Monterey Peninsula Herald, 7 July 1987. p. 23.

Anonymous. 1995. Fisherman pulls piranha from river near Easton. Pocono Record (August 1):5, Stroudsburg, Pennsylvania.

Anonymous. 1998. Editorial: The river that bites. Post-gazette.com. Available at URL http://www.post-gazette.com/forum/19981007edfish3.asp.

Anonymous. 2004. Hot Spot Fishing Records, Pacu. Available at URL http://www.hotspotfishing.com/records/default.asp.

Banek, T.J. - Fisheries Management Biologist, Missouri Department of Conservation, Springfield, MO.

Cochran, B. 1987. Jaws: fish caught in Roanoke River resembles tough cousin but is harmless. Roanoke Times & World-News, 3 October 1987. p. B1.

Courtenay, W.R., Jr. - Florida Atlantic University, Boca Raton, FL.

Courtenay, W.R., Jr., and D.A. Hensley. 1979. Survey of introduced non-native fishes. Phase I Report. Introduced exotic fishes in North America: status 1979. Report Submitted to National Fishery Research Laboratory, U.S. Fish and Wildlife Service, Gainesville, FL.

Courtenay, W.R., Jr., D.P. Jennings, and J.D. Williams. 1991. Appendix 2: exotic fishes. Pages 97-107 in Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott, eds. Common and scientific names of fishes from the United States and Canada, 5th edition. American Fisheries Society Special Publication 20. American Fisheries Society, Bethesda, MD.

Courtenay, W.R., Jr., D.A. Hensley, J.N. Taylor, and J.A. McCann. 1984. Distribution of exotic fishes in the continental United States. Pages 41-77 in W.R. Courtenay, Jr., and J.R. Stauffer, Jr., eds. Distribution, biology and management of exotic fishes. Johns Hopkins University Press, Baltimore, MD.

Fletcher, D. - Warmwater Fisheries Resource Manager, Washington Department of Wildlife, Olympia, WA. Response to NBS-G nonindigenous questionaire and other reports. 1992.

Gennings, R.M. - Georgia Department of Natural Resources, Atlanta, GA. Response to NBS-G nonindigenous questionaire.

Gilmore, G. - Harbor Branch Marine Institute, Fort Pierce, FL.

Gordon, B. 1987. Piranhas caught in Fresno County. San Francisco Chronicle, 8 July 1987. p. 31.

Horton, T. - Arkansas Fish and Wildlife Magazine, Little Rock, AR.

Howells, R.G., R.L. Benefield, and J.M. Mambretti. 1991. Records of pacus (Colossoma spp.) and piranhas (Serrasalmus spp.) in Texas. Texas Parks and Wildlife, Management Data Series 70, Austin, TX.

Jenkins, R.E., and N.M. Burkhead. 1994. Freshwater fishes of Virginia. American Fisheries Society, Bethesda, MD.

Logan, D.J., E.L. Bibles, and D.F. Markle. 1996. Recent collections of exotic aquarium fishes in the freshwaters of Oregon and thermal tolerance of Oriental weatherfish and pirapatinga. California Fish and Game 82(2):66-80.

Machado-Allison, A. 1982. Estudio sobre la subfamilia Serrasalminae (Teleostei, Characidae). Prte 1. Estudio comparado de los juveniles de las "cachamas" de Venezuela (generos Colossoma y Piaractus). Acta Biologica Venezuelica 11(3):1-101.

Marchand, N. 1998. Regional news: settling in. Outdoor Life Magazine 201(3):96.

Miller, J.B. - Division of Ichthyology, Florida Museum of Natural History, Gainesville, FL. (currently with Division of Recreation and Parks, Florida Park Service, Hobe Sound, FL)

Moreno, D. - Cleveland Metroparks Zoo, Cleveland, OH.

Rasmussen, J.L. 1998. Aquatic nuisance species of the Mississippi River basin. 60th Midwest Fish and Wildlife Conference, Aquatic Nuisance Species Symposium, Dec. 7, 1998, Cincinnati, OH.

Stroud, R.A. 1976. Ohio piranha. Sport Fishing Institute Bulletin 272:3.

Tilyou, G.A. - Inland Fish Division, Dept. of Wildlife and Fisheries, Baton Rouge, LA. Response to NBS-G nonindigenous questionaire. 1992.

Werner, R. - School of Environmental Science and Forestry, Syracuse University, Syracuse, NY.

Wright, S. 1995. Piranha or pacu ? it's still a whale of a fish tale. Northwest Arkansas Times (Fayetteville), 7 June 1995, 129(350):B6.

Other Resources:
Fact Sheet for Colossoma macropomum - USGS Nonindigenous Aquatic Species Database

Fact Sheet for Piaractus brachypomus - USGS Nonindigenous Aquatic Species Database

Fact Sheet for Piaractus mesopotamicus - USGS Nonindigenous Aquatic Species Database


Author: Nico, L.G., and Fuller, P.

Revision Date: 7/3/2019

Peer Review Date: 4/11/2006

Citation Information:
Nico, L.G., and Fuller, P., 2024, Colossoma or Piaractus sp.: U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?speciesID=419, Revision Date: 7/3/2019, Peer Review Date: 4/11/2006, Access Date: 6/22/2024

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.


The data represented on this site vary in accuracy, scale, completeness, extent of coverage and origin. It is the user's responsibility to use these data consistent with their intended purpose and within stated limitations. We highly recommend reviewing metadata files prior to interpreting these data.

Citation information: U.S. Geological Survey. [2024]. Nonindigenous Aquatic Species Database. Gainesville, Florida. Accessed [6/22/2024].

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