Common name: redhook pacu
Synonyms and Other Names: Myleus rubripinnis (Müller and Troschel, 1844)
available through www.itis.gov
Identification: The genus Myleus needs systematic review. See Géry (1977) for key, synonymy, and color photographs. According to Géry, Myleus rubripinnis represents a complex and seems to be composed of several different forms that are difficult to distinguish. Photographs of Myleus species appeared in Axelrod et al. (1985) and Sakurai et al. (1993).
Size: 15 cm SL.
Native Range: Tropical America. This species complex is widely distributed in lowland areas of South America east of the Andes, including the Amazon, Orinoco, and Parana (Paraguay River) basins and various coastal drainages of the Guianas (Géry 1977).
Hydrologic Unit Codes (HUCs) Explained
Puerto Rico &
Interactive maps: Point Distribution Maps
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 Myloplus rubripinnis are found here.
Table last updated 9/30/2019
† Populations may not be currently present.
Means of Introduction: The fish was probably an aquarium release.
Status: Reported in Massachusetts.
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.
References: (click for full references)
Axelrod, H. R., W. E. Burgess, N. Pronek, and J. G. Walls. 1985. Dr. Axelrod's atlas of freshwater aquarium fishes. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.
Cardoza, J. E., G. S. Jones, T.W. French, and D. B. Halliwell. 1993. Exotic and translocated vertebrates of Massachusetts, 2nd edition. Fauna of Massachusetts Series 6. Massachusetts Division of Fisheries and Wildlife, Publication 17223-110-200-11/93-C.R, Westborough, MA.
Géry, J. 1977. Characoids of the world. Tropical Fish Hobbyist Publications, Inc., Neptune City, NJ.
Hartel, K. E. 1992. Non-native fishes known from Massachusetts freshwaters. Occasional Reports of the Museum of Comparative Zoology, Harvard University, Fish Department, Cambridge, MA. 2. September. pp. 1-9.
Hartley, R. - Massachusetts Department of Fish and Wildlife, Westborough, MA.
Revision Date: 5/30/2004
Peer Review Date: 4/1/2016
Nico, L., 2019, Myloplus rubripinnis (Müller and Troschel, 1844): U.S. Geological Survey, Nonindigenous Aquatic Species Database, Gainesville, FL, https://nas.er.usgs.gov/queries/FactSheet.aspx?SpeciesID=425, Revision Date: 5/30/2004, Peer Review Date: 4/1/2016, Access Date: 10/20/2019
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.